1//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements semantic analysis for initializers.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/DeclObjC.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/AST/ExprObjC.h"
17#include "clang/AST/ExprOpenMP.h"
18#include "clang/AST/TypeLoc.h"
19#include "clang/Basic/CharInfo.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Basic/TargetInfo.h"
22#include "clang/Sema/Designator.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Lookup.h"
25#include "clang/Sema/SemaInternal.h"
26#include "llvm/ADT/APInt.h"
27#include "llvm/ADT/SmallString.h"
28#include "llvm/Support/ErrorHandling.h"
29#include "llvm/Support/raw_ostream.h"
30
31using namespace clang;
32
33//===----------------------------------------------------------------------===//
34// Sema Initialization Checking
35//===----------------------------------------------------------------------===//
36
37/// Check whether T is compatible with a wide character type (wchar_t,
38/// char16_t or char32_t).
39static bool IsWideCharCompatible(QualType T, ASTContext &Context) {
40 if (Context.typesAreCompatible(Context.getWideCharType(), T))
41 return true;
42 if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
43 return Context.typesAreCompatible(Context.Char16Ty, T) ||
44 Context.typesAreCompatible(Context.Char32Ty, T);
45 }
46 return false;
47}
48
49enum StringInitFailureKind {
50 SIF_None,
51 SIF_NarrowStringIntoWideChar,
52 SIF_WideStringIntoChar,
53 SIF_IncompatWideStringIntoWideChar,
54 SIF_UTF8StringIntoPlainChar,
55 SIF_PlainStringIntoUTF8Char,
56 SIF_Other
57};
58
59/// Check whether the array of type AT can be initialized by the Init
60/// expression by means of string initialization. Returns SIF_None if so,
61/// otherwise returns a StringInitFailureKind that describes why the
62/// initialization would not work.
63static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT,
64 ASTContext &Context) {
65 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
66 return SIF_Other;
67
68 // See if this is a string literal or @encode.
69 Init = Init->IgnoreParens();
70
71 // Handle @encode, which is a narrow string.
72 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
73 return SIF_None;
74
75 // Otherwise we can only handle string literals.
76 StringLiteral *SL = dyn_cast<StringLiteral>(Init);
77 if (!SL)
78 return SIF_Other;
79
80 const QualType ElemTy =
81 Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();
82
83 switch (SL->getKind()) {
84 case StringLiteral::UTF8:
85 // char8_t array can be initialized with a UTF-8 string.
86 if (ElemTy->isChar8Type())
87 return SIF_None;
88 LLVM_FALLTHROUGH;
89 case StringLiteral::Ascii:
90 // char array can be initialized with a narrow string.
91 // Only allow char x[] = "foo"; not char x[] = L"foo";
92 if (ElemTy->isCharType())
93 return (SL->getKind() == StringLiteral::UTF8 &&
94 Context.getLangOpts().Char8)
95 ? SIF_UTF8StringIntoPlainChar
96 : SIF_None;
97 if (ElemTy->isChar8Type())
98 return SIF_PlainStringIntoUTF8Char;
99 if (IsWideCharCompatible(ElemTy, Context))
100 return SIF_NarrowStringIntoWideChar;
101 return SIF_Other;
102 // C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
103 // "An array with element type compatible with a qualified or unqualified
104 // version of wchar_t, char16_t, or char32_t may be initialized by a wide
105 // string literal with the corresponding encoding prefix (L, u, or U,
106 // respectively), optionally enclosed in braces.
107 case StringLiteral::UTF16:
108 if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
109 return SIF_None;
110 if (ElemTy->isCharType() || ElemTy->isChar8Type())
111 return SIF_WideStringIntoChar;
112 if (IsWideCharCompatible(ElemTy, Context))
113 return SIF_IncompatWideStringIntoWideChar;
114 return SIF_Other;
115 case StringLiteral::UTF32:
116 if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
117 return SIF_None;
118 if (ElemTy->isCharType() || ElemTy->isChar8Type())
119 return SIF_WideStringIntoChar;
120 if (IsWideCharCompatible(ElemTy, Context))
121 return SIF_IncompatWideStringIntoWideChar;
122 return SIF_Other;
123 case StringLiteral::Wide:
124 if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
125 return SIF_None;
126 if (ElemTy->isCharType() || ElemTy->isChar8Type())
127 return SIF_WideStringIntoChar;
128 if (IsWideCharCompatible(ElemTy, Context))
129 return SIF_IncompatWideStringIntoWideChar;
130 return SIF_Other;
131 }
132
133 llvm_unreachable("missed a StringLiteral kind?");
134}
135
136static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
137 ASTContext &Context) {
138 const ArrayType *arrayType = Context.getAsArrayType(declType);
139 if (!arrayType)
140 return SIF_Other;
141 return IsStringInit(init, arrayType, Context);
142}
143
144bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
145 return ::IsStringInit(Init, AT, Context) == SIF_None;
146}
147
148/// Update the type of a string literal, including any surrounding parentheses,
149/// to match the type of the object which it is initializing.
150static void updateStringLiteralType(Expr *E, QualType Ty) {
151 while (true) {
152 E->setType(Ty);
153 E->setValueKind(VK_RValue);
154 if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) {
155 break;
156 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
157 E = PE->getSubExpr();
158 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
159 assert(UO->getOpcode() == UO_Extension);
160 E = UO->getSubExpr();
161 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
162 E = GSE->getResultExpr();
163 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
164 E = CE->getChosenSubExpr();
165 } else {
166 llvm_unreachable("unexpected expr in string literal init");
167 }
168 }
169}
170
171/// Fix a compound literal initializing an array so it's correctly marked
172/// as an rvalue.
173static void updateGNUCompoundLiteralRValue(Expr *E) {
174 while (true) {
175 E->setValueKind(VK_RValue);
176 if (isa<CompoundLiteralExpr>(E)) {
177 break;
178 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
179 E = PE->getSubExpr();
180 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
181 assert(UO->getOpcode() == UO_Extension);
182 E = UO->getSubExpr();
183 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
184 E = GSE->getResultExpr();
185 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
186 E = CE->getChosenSubExpr();
187 } else {
188 llvm_unreachable("unexpected expr in array compound literal init");
189 }
190 }
191}
192
193static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
194 Sema &S) {
195 // Get the length of the string as parsed.
196 auto *ConstantArrayTy =
197 cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
198 uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();
199
200 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
201 // C99 6.7.8p14. We have an array of character type with unknown size
202 // being initialized to a string literal.
203 llvm::APInt ConstVal(32, StrLength);
204 // Return a new array type (C99 6.7.8p22).
205 DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
206 ConstVal, nullptr,
207 ArrayType::Normal, 0);
208 updateStringLiteralType(Str, DeclT);
209 return;
210 }
211
212 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
213
214 // We have an array of character type with known size. However,
215 // the size may be smaller or larger than the string we are initializing.
216 // FIXME: Avoid truncation for 64-bit length strings.
217 if (S.getLangOpts().CPlusPlus) {
218 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
219 // For Pascal strings it's OK to strip off the terminating null character,
220 // so the example below is valid:
221 //
222 // unsigned char a[2] = "\pa";
223 if (SL->isPascal())
224 StrLength--;
225 }
226
227 // [dcl.init.string]p2
228 if (StrLength > CAT->getSize().getZExtValue())
229 S.Diag(Str->getBeginLoc(),
230 diag::err_initializer_string_for_char_array_too_long)
231 << Str->getSourceRange();
232 } else {
233 // C99 6.7.8p14.
234 if (StrLength-1 > CAT->getSize().getZExtValue())
235 S.Diag(Str->getBeginLoc(),
236 diag::ext_initializer_string_for_char_array_too_long)
237 << Str->getSourceRange();
238 }
239
240 // Set the type to the actual size that we are initializing. If we have
241 // something like:
242 // char x[1] = "foo";
243 // then this will set the string literal's type to char[1].
244 updateStringLiteralType(Str, DeclT);
245}
246
247//===----------------------------------------------------------------------===//
248// Semantic checking for initializer lists.
249//===----------------------------------------------------------------------===//
250
251namespace {
252
253/// Semantic checking for initializer lists.
254///
255/// The InitListChecker class contains a set of routines that each
256/// handle the initialization of a certain kind of entity, e.g.,
257/// arrays, vectors, struct/union types, scalars, etc. The
258/// InitListChecker itself performs a recursive walk of the subobject
259/// structure of the type to be initialized, while stepping through
260/// the initializer list one element at a time. The IList and Index
261/// parameters to each of the Check* routines contain the active
262/// (syntactic) initializer list and the index into that initializer
263/// list that represents the current initializer. Each routine is
264/// responsible for moving that Index forward as it consumes elements.
265///
266/// Each Check* routine also has a StructuredList/StructuredIndex
267/// arguments, which contains the current "structured" (semantic)
268/// initializer list and the index into that initializer list where we
269/// are copying initializers as we map them over to the semantic
270/// list. Once we have completed our recursive walk of the subobject
271/// structure, we will have constructed a full semantic initializer
272/// list.
273///
274/// C99 designators cause changes in the initializer list traversal,
275/// because they make the initialization "jump" into a specific
276/// subobject and then continue the initialization from that
277/// point. CheckDesignatedInitializer() recursively steps into the
278/// designated subobject and manages backing out the recursion to
279/// initialize the subobjects after the one designated.
280///
281/// If an initializer list contains any designators, we build a placeholder
282/// structured list even in 'verify only' mode, so that we can track which
283/// elements need 'empty' initializtion.
284class InitListChecker {
285 Sema &SemaRef;
286 bool hadError = false;
287 bool VerifyOnly; // No diagnostics.
288 bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
289 bool InOverloadResolution;
290 InitListExpr *FullyStructuredList = nullptr;
291 NoInitExpr *DummyExpr = nullptr;
292
293 NoInitExpr *getDummyInit() {
294 if (!DummyExpr)
295 DummyExpr = new (SemaRef.Context) NoInitExpr(SemaRef.Context.VoidTy);
296 return DummyExpr;
297 }
298
299 void CheckImplicitInitList(const InitializedEntity &Entity,
300 InitListExpr *ParentIList, QualType T,
301 unsigned &Index, InitListExpr *StructuredList,
302 unsigned &StructuredIndex);
303 void CheckExplicitInitList(const InitializedEntity &Entity,
304 InitListExpr *IList, QualType &T,
305 InitListExpr *StructuredList,
306 bool TopLevelObject = false);
307 void CheckListElementTypes(const InitializedEntity &Entity,
308 InitListExpr *IList, QualType &DeclType,
309 bool SubobjectIsDesignatorContext,
310 unsigned &Index,
311 InitListExpr *StructuredList,
312 unsigned &StructuredIndex,
313 bool TopLevelObject = false);
314 void CheckSubElementType(const InitializedEntity &Entity,
315 InitListExpr *IList, QualType ElemType,
316 unsigned &Index,
317 InitListExpr *StructuredList,
318 unsigned &StructuredIndex);
319 void CheckComplexType(const InitializedEntity &Entity,
320 InitListExpr *IList, QualType DeclType,
321 unsigned &Index,
322 InitListExpr *StructuredList,
323 unsigned &StructuredIndex);
324 void CheckScalarType(const InitializedEntity &Entity,
325 InitListExpr *IList, QualType DeclType,
326 unsigned &Index,
327 InitListExpr *StructuredList,
328 unsigned &StructuredIndex);
329 void CheckReferenceType(const InitializedEntity &Entity,
330 InitListExpr *IList, QualType DeclType,
331 unsigned &Index,
332 InitListExpr *StructuredList,
333 unsigned &StructuredIndex);
334 void CheckVectorType(const InitializedEntity &Entity,
335 InitListExpr *IList, QualType DeclType, unsigned &Index,
336 InitListExpr *StructuredList,
337 unsigned &StructuredIndex);
338 void CheckStructUnionTypes(const InitializedEntity &Entity,
339 InitListExpr *IList, QualType DeclType,
340 CXXRecordDecl::base_class_range Bases,
341 RecordDecl::field_iterator Field,
342 bool SubobjectIsDesignatorContext, unsigned &Index,
343 InitListExpr *StructuredList,
344 unsigned &StructuredIndex,
345 bool TopLevelObject = false);
346 void CheckArrayType(const InitializedEntity &Entity,
347 InitListExpr *IList, QualType &DeclType,
348 llvm::APSInt elementIndex,
349 bool SubobjectIsDesignatorContext, unsigned &Index,
350 InitListExpr *StructuredList,
351 unsigned &StructuredIndex);
352 bool CheckDesignatedInitializer(const InitializedEntity &Entity,
353 InitListExpr *IList, DesignatedInitExpr *DIE,
354 unsigned DesigIdx,
355 QualType &CurrentObjectType,
356 RecordDecl::field_iterator *NextField,
357 llvm::APSInt *NextElementIndex,
358 unsigned &Index,
359 InitListExpr *StructuredList,
360 unsigned &StructuredIndex,
361 bool FinishSubobjectInit,
362 bool TopLevelObject);
363 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
364 QualType CurrentObjectType,
365 InitListExpr *StructuredList,
366 unsigned StructuredIndex,
367 SourceRange InitRange,
368 bool IsFullyOverwritten = false);
369 void UpdateStructuredListElement(InitListExpr *StructuredList,
370 unsigned &StructuredIndex,
371 Expr *expr);
372 InitListExpr *createInitListExpr(QualType CurrentObjectType,
373 SourceRange InitRange,
374 unsigned ExpectedNumInits);
375 int numArrayElements(QualType DeclType);
376 int numStructUnionElements(QualType DeclType);
377
378 ExprResult PerformEmptyInit(SourceLocation Loc,
379 const InitializedEntity &Entity);
380
381 /// Diagnose that OldInit (or part thereof) has been overridden by NewInit.
382 void diagnoseInitOverride(Expr *OldInit, SourceRange NewInitRange,
383 bool FullyOverwritten = true) {
384 // Overriding an initializer via a designator is valid with C99 designated
385 // initializers, but ill-formed with C++20 designated initializers.
386 unsigned DiagID = SemaRef.getLangOpts().CPlusPlus
387 ? diag::ext_initializer_overrides
388 : diag::warn_initializer_overrides;
389
390 if (InOverloadResolution && SemaRef.getLangOpts().CPlusPlus) {
391 // In overload resolution, we have to strictly enforce the rules, and so
392 // don't allow any overriding of prior initializers. This matters for a
393 // case such as:
394 //
395 // union U { int a, b; };
396 // struct S { int a, b; };
397 // void f(U), f(S);
398 //
399 // Here, f({.a = 1, .b = 2}) is required to call the struct overload. For
400 // consistency, we disallow all overriding of prior initializers in
401 // overload resolution, not only overriding of union members.
402 hadError = true;
403 } else if (OldInit->getType().isDestructedType() && !FullyOverwritten) {
404 // If we'll be keeping around the old initializer but overwriting part of
405 // the object it initialized, and that object is not trivially
406 // destructible, this can leak. Don't allow that, not even as an
407 // extension.
408 //
409 // FIXME: It might be reasonable to allow this in cases where the part of
410 // the initializer that we're overriding has trivial destruction.
411 DiagID = diag::err_initializer_overrides_destructed;
412 } else if (!OldInit->getSourceRange().isValid()) {
413 // We need to check on source range validity because the previous
414 // initializer does not have to be an explicit initializer. e.g.,
415 //
416 // struct P { int a, b; };
417 // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
418 //
419 // There is an overwrite taking place because the first braced initializer
420 // list "{ .a = 2 }" already provides value for .p.b (which is zero).
421 //
422 // Such overwrites are harmless, so we don't diagnose them. (Note that in
423 // C++, this cannot be reached unless we've already seen and diagnosed a
424 // different conformance issue, such as a mixture of designated and
425 // non-designated initializers or a multi-level designator.)
426 return;
427 }
428
429 if (!VerifyOnly) {
430 SemaRef.Diag(NewInitRange.getBegin(), DiagID)
431 << NewInitRange << FullyOverwritten << OldInit->getType();
432 SemaRef.Diag(OldInit->getBeginLoc(), diag::note_previous_initializer)
433 << (OldInit->HasSideEffects(SemaRef.Context) && FullyOverwritten)
434 << OldInit->getSourceRange();
435 }
436 }
437
438 // Explanation on the "FillWithNoInit" mode:
439 //
440 // Assume we have the following definitions (Case#1):
441 // struct P { char x[6][6]; } xp = { .x[1] = "bar" };
442 // struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
443 //
444 // l.lp.x[1][0..1] should not be filled with implicit initializers because the
445 // "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
446 //
447 // But if we have (Case#2):
448 // struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
449 //
450 // l.lp.x[1][0..1] are implicitly initialized and do not use values from the
451 // "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
452 //
453 // To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
454 // in the InitListExpr, the "holes" in Case#1 are filled not with empty
455 // initializers but with special "NoInitExpr" place holders, which tells the
456 // CodeGen not to generate any initializers for these parts.
457 void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
458 const InitializedEntity &ParentEntity,
459 InitListExpr *ILE, bool &RequiresSecondPass,
460 bool FillWithNoInit);
461 void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
462 const InitializedEntity &ParentEntity,
463 InitListExpr *ILE, bool &RequiresSecondPass,
464 bool FillWithNoInit = false);
465 void FillInEmptyInitializations(const InitializedEntity &Entity,
466 InitListExpr *ILE, bool &RequiresSecondPass,
467 InitListExpr *OuterILE, unsigned OuterIndex,
468 bool FillWithNoInit = false);
469 bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
470 Expr *InitExpr, FieldDecl *Field,
471 bool TopLevelObject);
472 void CheckEmptyInitializable(const InitializedEntity &Entity,
473 SourceLocation Loc);
474
475public:
476 InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
477 QualType &T, bool VerifyOnly, bool TreatUnavailableAsInvalid,
478 bool InOverloadResolution = false);
479 bool HadError() { return hadError; }
480
481 // Retrieves the fully-structured initializer list used for
482 // semantic analysis and code generation.
483 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
484};
485
486} // end anonymous namespace
487
488ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
489 const InitializedEntity &Entity) {
490 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
491 true);
492 MultiExprArg SubInit;
493 Expr *InitExpr;
494 InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc);
495
496 // C++ [dcl.init.aggr]p7:
497 // If there are fewer initializer-clauses in the list than there are
498 // members in the aggregate, then each member not explicitly initialized
499 // ...
500 bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
501 Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
502 if (EmptyInitList) {
503 // C++1y / DR1070:
504 // shall be initialized [...] from an empty initializer list.
505 //
506 // We apply the resolution of this DR to C++11 but not C++98, since C++98
507 // does not have useful semantics for initialization from an init list.
508 // We treat this as copy-initialization, because aggregate initialization
509 // always performs copy-initialization on its elements.
510 //
511 // Only do this if we're initializing a class type, to avoid filling in
512 // the initializer list where possible.
513 InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context)
514 InitListExpr(SemaRef.Context, Loc, None, Loc);
515 InitExpr->setType(SemaRef.Context.VoidTy);
516 SubInit = InitExpr;
517 Kind = InitializationKind::CreateCopy(Loc, Loc);
518 } else {
519 // C++03:
520 // shall be value-initialized.
521 }
522
523 InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
524 // libstdc++4.6 marks the vector default constructor as explicit in
525 // _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
526 // stlport does so too. Look for std::__debug for libstdc++, and for
527 // std:: for stlport. This is effectively a compiler-side implementation of
528 // LWG2193.
529 if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
530 InitializationSequence::FK_ExplicitConstructor) {
531 OverloadCandidateSet::iterator Best;
532 OverloadingResult O =
533 InitSeq.getFailedCandidateSet()
534 .BestViableFunction(SemaRef, Kind.getLocation(), Best);
535 (void)O;
536 assert(O == OR_Success && "Inconsistent overload resolution");
537 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
538 CXXRecordDecl *R = CtorDecl->getParent();
539
540 if (CtorDecl->getMinRequiredArguments() == 0 &&
541 CtorDecl->isExplicit() && R->getDeclName() &&
542 SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
543 bool IsInStd = false;
544 for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
545 ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
546 if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
547 IsInStd = true;
548 }
549
550 if (IsInStd && llvm::StringSwitch<bool>(R->getName())
551 .Cases("basic_string", "deque", "forward_list", true)
552 .Cases("list", "map", "multimap", "multiset", true)
553 .Cases("priority_queue", "queue", "set", "stack", true)
554 .Cases("unordered_map", "unordered_set", "vector", true)
555 .Default(false)) {
556 InitSeq.InitializeFrom(
557 SemaRef, Entity,
558 InitializationKind::CreateValue(Loc, Loc, Loc, true),
559 MultiExprArg(), /*TopLevelOfInitList=*/false,
560 TreatUnavailableAsInvalid);
561 // Emit a warning for this. System header warnings aren't shown
562 // by default, but people working on system headers should see it.
563 if (!VerifyOnly) {
564 SemaRef.Diag(CtorDecl->getLocation(),
565 diag::warn_invalid_initializer_from_system_header);
566 if (Entity.getKind() == InitializedEntity::EK_Member)
567 SemaRef.Diag(Entity.getDecl()->getLocation(),
568 diag::note_used_in_initialization_here);
569 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
570 SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
571 }
572 }
573 }
574 }
575 if (!InitSeq) {
576 if (!VerifyOnly) {
577 InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
578 if (Entity.getKind() == InitializedEntity::EK_Member)
579 SemaRef.Diag(Entity.getDecl()->getLocation(),
580 diag::note_in_omitted_aggregate_initializer)
581 << /*field*/1 << Entity.getDecl();
582 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) {
583 bool IsTrailingArrayNewMember =
584 Entity.getParent() &&
585 Entity.getParent()->isVariableLengthArrayNew();
586 SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
587 << (IsTrailingArrayNewMember ? 2 : /*array element*/0)
588 << Entity.getElementIndex();
589 }
590 }
591 hadError = true;
592 return ExprError();
593 }
594
595 return VerifyOnly ? ExprResult()
596 : InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
597}
598
599void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
600 SourceLocation Loc) {
601 // If we're building a fully-structured list, we'll check this at the end
602 // once we know which elements are actually initialized. Otherwise, we know
603 // that there are no designators so we can just check now.
604 if (FullyStructuredList)
605 return;
606 PerformEmptyInit(Loc, Entity);
607}
608
609void InitListChecker::FillInEmptyInitForBase(
610 unsigned Init, const CXXBaseSpecifier &Base,
611 const InitializedEntity &ParentEntity, InitListExpr *ILE,
612 bool &RequiresSecondPass, bool FillWithNoInit) {
613 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
614 SemaRef.Context, &Base, false, &ParentEntity);
615
616 if (Init >= ILE->getNumInits() || !ILE->getInit(Init)) {
617 ExprResult BaseInit = FillWithNoInit
618 ? new (SemaRef.Context) NoInitExpr(Base.getType())
619 : PerformEmptyInit(ILE->getEndLoc(), BaseEntity);
620 if (BaseInit.isInvalid()) {
621 hadError = true;
622 return;
623 }
624
625 if (!VerifyOnly) {
626 assert(Init < ILE->getNumInits() && "should have been expanded");
627 ILE->setInit(Init, BaseInit.getAs<Expr>());
628 }
629 } else if (InitListExpr *InnerILE =
630 dyn_cast<InitListExpr>(ILE->getInit(Init))) {
631 FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
632 ILE, Init, FillWithNoInit);
633 } else if (DesignatedInitUpdateExpr *InnerDIUE =
634 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
635 FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
636 RequiresSecondPass, ILE, Init,
637 /*FillWithNoInit =*/true);
638 }
639}
640
641void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
642 const InitializedEntity &ParentEntity,
643 InitListExpr *ILE,
644 bool &RequiresSecondPass,
645 bool FillWithNoInit) {
646 SourceLocation Loc = ILE->getEndLoc();
647 unsigned NumInits = ILE->getNumInits();
648 InitializedEntity MemberEntity
649 = InitializedEntity::InitializeMember(Field, &ParentEntity);
650
651 if (Init >= NumInits || !ILE->getInit(Init)) {
652 if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
653 if (!RType->getDecl()->isUnion())
654 assert((Init < NumInits || VerifyOnly) &&
655 "This ILE should have been expanded");
656
657 if (FillWithNoInit) {
658 assert(!VerifyOnly && "should not fill with no-init in verify-only mode");
659 Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
660 if (Init < NumInits)
661 ILE->setInit(Init, Filler);
662 else
663 ILE->updateInit(SemaRef.Context, Init, Filler);
664 return;
665 }
666 // C++1y [dcl.init.aggr]p7:
667 // If there are fewer initializer-clauses in the list than there are
668 // members in the aggregate, then each member not explicitly initialized
669 // shall be initialized from its brace-or-equal-initializer [...]
670 if (Field->hasInClassInitializer()) {
671 if (VerifyOnly)
672 return;
673
674 ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
675 if (DIE.isInvalid()) {
676 hadError = true;
677 return;
678 }
679 SemaRef.checkInitializerLifetime(MemberEntity, DIE.get());
680 if (Init < NumInits)
681 ILE->setInit(Init, DIE.get());
682 else {
683 ILE->updateInit(SemaRef.Context, Init, DIE.get());
684 RequiresSecondPass = true;
685 }
686 return;
687 }
688
689 if (Field->getType()->isReferenceType()) {
690 if (!VerifyOnly) {
691 // C++ [dcl.init.aggr]p9:
692 // If an incomplete or empty initializer-list leaves a
693 // member of reference type uninitialized, the program is
694 // ill-formed.
695 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
696 << Field->getType()
697 << ILE->getSyntacticForm()->getSourceRange();
698 SemaRef.Diag(Field->getLocation(),
699 diag::note_uninit_reference_member);
700 }
701 hadError = true;
702 return;
703 }
704
705 ExprResult MemberInit = PerformEmptyInit(Loc, MemberEntity);
706 if (MemberInit.isInvalid()) {
707 hadError = true;
708 return;
709 }
710
711 if (hadError || VerifyOnly) {
712 // Do nothing
713 } else if (Init < NumInits) {
714 ILE->setInit(Init, MemberInit.getAs<Expr>());
715 } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
716 // Empty initialization requires a constructor call, so
717 // extend the initializer list to include the constructor
718 // call and make a note that we'll need to take another pass
719 // through the initializer list.
720 ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
721 RequiresSecondPass = true;
722 }
723 } else if (InitListExpr *InnerILE
724 = dyn_cast<InitListExpr>(ILE->getInit(Init))) {
725 FillInEmptyInitializations(MemberEntity, InnerILE,
726 RequiresSecondPass, ILE, Init, FillWithNoInit);
727 } else if (DesignatedInitUpdateExpr *InnerDIUE =
728 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
729 FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
730 RequiresSecondPass, ILE, Init,
731 /*FillWithNoInit =*/true);
732 }
733}
734
735/// Recursively replaces NULL values within the given initializer list
736/// with expressions that perform value-initialization of the
737/// appropriate type, and finish off the InitListExpr formation.
738void
739InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
740 InitListExpr *ILE,
741 bool &RequiresSecondPass,
742 InitListExpr *OuterILE,
743 unsigned OuterIndex,
744 bool FillWithNoInit) {
745 assert((ILE->getType() != SemaRef.Context.VoidTy) &&
746 "Should not have void type");
747
748 // We don't need to do any checks when just filling NoInitExprs; that can't
749 // fail.
750 if (FillWithNoInit && VerifyOnly)
751 return;
752
753 // If this is a nested initializer list, we might have changed its contents
754 // (and therefore some of its properties, such as instantiation-dependence)
755 // while filling it in. Inform the outer initializer list so that its state
756 // can be updated to match.
757 // FIXME: We should fully build the inner initializers before constructing
758 // the outer InitListExpr instead of mutating AST nodes after they have
759 // been used as subexpressions of other nodes.
760 struct UpdateOuterILEWithUpdatedInit {
761 InitListExpr *Outer;
762 unsigned OuterIndex;
763 ~UpdateOuterILEWithUpdatedInit() {
764 if (Outer)
765 Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
766 }
767 } UpdateOuterRAII = {OuterILE, OuterIndex};
768
769 // A transparent ILE is not performing aggregate initialization and should
770 // not be filled in.
771 if (ILE->isTransparent())
772 return;
773
774 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
775 const RecordDecl *RDecl = RType->getDecl();
776 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
777 FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
778 Entity, ILE, RequiresSecondPass, FillWithNoInit);
779 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
780 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
781 for (auto *Field : RDecl->fields()) {
782 if (Field->hasInClassInitializer()) {
783 FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
784 FillWithNoInit);
785 break;
786 }
787 }
788 } else {
789 // The fields beyond ILE->getNumInits() are default initialized, so in
790 // order to leave them uninitialized, the ILE is expanded and the extra
791 // fields are then filled with NoInitExpr.
792 unsigned NumElems = numStructUnionElements(ILE->getType());
793 if (RDecl->hasFlexibleArrayMember())
794 ++NumElems;
795 if (!VerifyOnly && ILE->getNumInits() < NumElems)
796 ILE->resizeInits(SemaRef.Context, NumElems);
797
798 unsigned Init = 0;
799
800 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
801 for (auto &Base : CXXRD->bases()) {
802 if (hadError)
803 return;
804
805 FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
806 FillWithNoInit);
807 ++Init;
808 }
809 }
810
811 for (auto *Field : RDecl->fields()) {
812 if (Field->isUnnamedBitfield())
813 continue;
814
815 if (hadError)
816 return;
817
818 FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
819 FillWithNoInit);
820 if (hadError)
821 return;
822
823 ++Init;
824
825 // Only look at the first initialization of a union.
826 if (RDecl->isUnion())
827 break;
828 }
829 }
830
831 return;
832 }
833
834 QualType ElementType;
835
836 InitializedEntity ElementEntity = Entity;
837 unsigned NumInits = ILE->getNumInits();
838 unsigned NumElements = NumInits;
839 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
840 ElementType = AType->getElementType();
841 if (const auto *CAType = dyn_cast<ConstantArrayType>(AType))
842 NumElements = CAType->getSize().getZExtValue();
843 // For an array new with an unknown bound, ask for one additional element
844 // in order to populate the array filler.
845 if (Entity.isVariableLengthArrayNew())
846 ++NumElements;
847 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
848 0, Entity);
849 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
850 ElementType = VType->getElementType();
851 NumElements = VType->getNumElements();
852 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
853 0, Entity);
854 } else
855 ElementType = ILE->getType();
856
857 bool SkipEmptyInitChecks = false;
858 for (unsigned Init = 0; Init != NumElements; ++Init) {
859 if (hadError)
860 return;
861
862 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
863 ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
864 ElementEntity.setElementIndex(Init);
865
866 if (Init >= NumInits && (ILE->hasArrayFiller() || SkipEmptyInitChecks))
867 return;
868
869 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
870 if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
871 ILE->setInit(Init, ILE->getArrayFiller());
872 else if (!InitExpr && !ILE->hasArrayFiller()) {
873 // In VerifyOnly mode, there's no point performing empty initialization
874 // more than once.
875 if (SkipEmptyInitChecks)
876 continue;
877
878 Expr *Filler = nullptr;
879
880 if (FillWithNoInit)
881 Filler = new (SemaRef.Context) NoInitExpr(ElementType);
882 else {
883 ExprResult ElementInit =
884 PerformEmptyInit(ILE->getEndLoc(), ElementEntity);
885 if (ElementInit.isInvalid()) {
886 hadError = true;
887 return;
888 }
889
890 Filler = ElementInit.getAs<Expr>();
891 }
892
893 if (hadError) {
894 // Do nothing
895 } else if (VerifyOnly) {
896 SkipEmptyInitChecks = true;
897 } else if (Init < NumInits) {
898 // For arrays, just set the expression used for value-initialization
899 // of the "holes" in the array.
900 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
901 ILE->setArrayFiller(Filler);
902 else
903 ILE->setInit(Init, Filler);
904 } else {
905 // For arrays, just set the expression used for value-initialization
906 // of the rest of elements and exit.
907 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
908 ILE->setArrayFiller(Filler);
909 return;
910 }
911
912 if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
913 // Empty initialization requires a constructor call, so
914 // extend the initializer list to include the constructor
915 // call and make a note that we'll need to take another pass
916 // through the initializer list.
917 ILE->updateInit(SemaRef.Context, Init, Filler);
918 RequiresSecondPass = true;
919 }
920 }
921 } else if (InitListExpr *InnerILE
922 = dyn_cast_or_null<InitListExpr>(InitExpr)) {
923 FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
924 ILE, Init, FillWithNoInit);
925 } else if (DesignatedInitUpdateExpr *InnerDIUE =
926 dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr)) {
927 FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
928 RequiresSecondPass, ILE, Init,
929 /*FillWithNoInit =*/true);
930 }
931 }
932}
933
934static bool hasAnyDesignatedInits(const InitListExpr *IL) {
935 for (const Stmt *Init : *IL)
936 if (Init && isa<DesignatedInitExpr>(Init))
937 return true;
938 return false;
939}
940
941InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
942 InitListExpr *IL, QualType &T, bool VerifyOnly,
943 bool TreatUnavailableAsInvalid,
944 bool InOverloadResolution)
945 : SemaRef(S), VerifyOnly(VerifyOnly),
946 TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
947 InOverloadResolution(InOverloadResolution) {
948 if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
949 FullyStructuredList =
950 createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
951
952 // FIXME: Check that IL isn't already the semantic form of some other
953 // InitListExpr. If it is, we'd create a broken AST.
954 if (!VerifyOnly)
955 FullyStructuredList->setSyntacticForm(IL);
956 }
957
958 CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
959 /*TopLevelObject=*/true);
960
961 if (!hadError && FullyStructuredList) {
962 bool RequiresSecondPass = false;
963 FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
964 /*OuterILE=*/nullptr, /*OuterIndex=*/0);
965 if (RequiresSecondPass && !hadError)
966 FillInEmptyInitializations(Entity, FullyStructuredList,
967 RequiresSecondPass, nullptr, 0);
968 }
969 if (hadError && FullyStructuredList)
970 FullyStructuredList->markError();
971}
972
973int InitListChecker::numArrayElements(QualType DeclType) {
974 // FIXME: use a proper constant
975 int maxElements = 0x7FFFFFFF;
976 if (const ConstantArrayType *CAT =
977 SemaRef.Context.getAsConstantArrayType(DeclType)) {
978 maxElements = static_cast<int>(CAT->getSize().getZExtValue());
979 }
980 return maxElements;
981}
982
983int InitListChecker::numStructUnionElements(QualType DeclType) {
984 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
985 int InitializableMembers = 0;
986 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
987 InitializableMembers += CXXRD->getNumBases();
988 for (const auto *Field : structDecl->fields())
989 if (!Field->isUnnamedBitfield())
990 ++InitializableMembers;
991
992 if (structDecl->isUnion())
993 return std::min(InitializableMembers, 1);
994 return InitializableMembers - structDecl->hasFlexibleArrayMember();
995}
996
997/// Determine whether Entity is an entity for which it is idiomatic to elide
998/// the braces in aggregate initialization.
999static bool isIdiomaticBraceElisionEntity(const InitializedEntity &Entity) {
1000 // Recursive initialization of the one and only field within an aggregate
1001 // class is considered idiomatic. This case arises in particular for
1002 // initialization of std::array, where the C++ standard suggests the idiom of
1003 //
1004 // std::array<T, N> arr = {1, 2, 3};
1005 //
1006 // (where std::array is an aggregate struct containing a single array field.
1007
1008 // FIXME: Should aggregate initialization of a struct with a single
1009 // base class and no members also suppress the warning?
1010 if (Entity.getKind() != InitializedEntity::EK_Member || !Entity.getParent())
1011 return false;
1012
1013 auto *ParentRD =
1014 Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
1015 if (CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(ParentRD))
1016 if (CXXRD->getNumBases())
1017 return false;
1018
1019 auto FieldIt = ParentRD->field_begin();
1020 assert(FieldIt != ParentRD->field_end() &&
1021 "no fields but have initializer for member?");
1022 return ++FieldIt == ParentRD->field_end();
1023}
1024
1025/// Check whether the range of the initializer \p ParentIList from element
1026/// \p Index onwards can be used to initialize an object of type \p T. Update
1027/// \p Index to indicate how many elements of the list were consumed.
1028///
1029/// This also fills in \p StructuredList, from element \p StructuredIndex
1030/// onwards, with the fully-braced, desugared form of the initialization.
1031void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
1032 InitListExpr *ParentIList,
1033 QualType T, unsigned &Index,
1034 InitListExpr *StructuredList,
1035 unsigned &StructuredIndex) {
1036 int maxElements = 0;
1037
1038 if (T->isArrayType())
1039 maxElements = numArrayElements(T);
1040 else if (T->isRecordType())
1041 maxElements = numStructUnionElements(T);
1042 else if (T->isVectorType())
1043 maxElements = T->castAs<VectorType>()->getNumElements();
1044 else
1045 llvm_unreachable("CheckImplicitInitList(): Illegal type");
1046
1047 if (maxElements == 0) {
1048 if (!VerifyOnly)
1049 SemaRef.Diag(ParentIList->getInit(Index)->getBeginLoc(),
1050 diag::err_implicit_empty_initializer);
1051 ++Index;
1052 hadError = true;
1053 return;
1054 }
1055
1056 // Build a structured initializer list corresponding to this subobject.
1057 InitListExpr *StructuredSubobjectInitList = getStructuredSubobjectInit(
1058 ParentIList, Index, T, StructuredList, StructuredIndex,
1059 SourceRange(ParentIList->getInit(Index)->getBeginLoc(),
1060 ParentIList->getSourceRange().getEnd()));
1061 unsigned StructuredSubobjectInitIndex = 0;
1062
1063 // Check the element types and build the structural subobject.
1064 unsigned StartIndex = Index;
1065 CheckListElementTypes(Entity, ParentIList, T,
1066 /*SubobjectIsDesignatorContext=*/false, Index,
1067 StructuredSubobjectInitList,
1068 StructuredSubobjectInitIndex);
1069
1070 if (StructuredSubobjectInitList) {
1071 StructuredSubobjectInitList->setType(T);
1072
1073 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
1074 // Update the structured sub-object initializer so that it's ending
1075 // range corresponds with the end of the last initializer it used.
1076 if (EndIndex < ParentIList->getNumInits() &&
1077 ParentIList->getInit(EndIndex)) {
1078 SourceLocation EndLoc
1079 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
1080 StructuredSubobjectInitList->setRBraceLoc(EndLoc);
1081 }
1082
1083 // Complain about missing braces.
1084 if (!VerifyOnly && (T->isArrayType() || T->isRecordType()) &&
1085 !ParentIList->isIdiomaticZeroInitializer(SemaRef.getLangOpts()) &&
1086 !isIdiomaticBraceElisionEntity(Entity)) {
1087 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1088 diag::warn_missing_braces)
1089 << StructuredSubobjectInitList->getSourceRange()
1090 << FixItHint::CreateInsertion(
1091 StructuredSubobjectInitList->getBeginLoc(), "{")
1092 << FixItHint::CreateInsertion(
1093 SemaRef.getLocForEndOfToken(
1094 StructuredSubobjectInitList->getEndLoc()),
1095 "}");
1096 }
1097
1098 // Warn if this type won't be an aggregate in future versions of C++.
1099 auto *CXXRD = T->getAsCXXRecordDecl();
1100 if (!VerifyOnly && CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1101 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1102 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1103 << StructuredSubobjectInitList->getSourceRange() << T;
1104 }
1105 }
1106}
1107
1108/// Warn that \p Entity was of scalar type and was initialized by a
1109/// single-element braced initializer list.
1110static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
1111 SourceRange Braces) {
1112 // Don't warn during template instantiation. If the initialization was
1113 // non-dependent, we warned during the initial parse; otherwise, the
1114 // type might not be scalar in some uses of the template.
1115 if (S.inTemplateInstantiation())
1116 return;
1117
1118 unsigned DiagID = 0;
1119
1120 switch (Entity.getKind()) {
1121 case InitializedEntity::EK_VectorElement:
1122 case InitializedEntity::EK_ComplexElement:
1123 case InitializedEntity::EK_ArrayElement:
1124 case InitializedEntity::EK_Parameter:
1125 case InitializedEntity::EK_Parameter_CF_Audited:
1126 case InitializedEntity::EK_TemplateParameter:
1127 case InitializedEntity::EK_Result:
1128 // Extra braces here are suspicious.
1129 DiagID = diag::warn_braces_around_init;
1130 break;
1131
1132 case InitializedEntity::EK_Member:
1133 // Warn on aggregate initialization but not on ctor init list or
1134 // default member initializer.
1135 if (Entity.getParent())
1136 DiagID = diag::warn_braces_around_init;
1137 break;
1138
1139 case InitializedEntity::EK_Variable:
1140 case InitializedEntity::EK_LambdaCapture:
1141 // No warning, might be direct-list-initialization.
1142 // FIXME: Should we warn for copy-list-initialization in these cases?
1143 break;
1144
1145 case InitializedEntity::EK_New:
1146 case InitializedEntity::EK_Temporary:
1147 case InitializedEntity::EK_CompoundLiteralInit:
1148 // No warning, braces are part of the syntax of the underlying construct.
1149 break;
1150
1151 case InitializedEntity::EK_RelatedResult:
1152 // No warning, we already warned when initializing the result.
1153 break;
1154
1155 case InitializedEntity::EK_Exception:
1156 case InitializedEntity::EK_Base:
1157 case InitializedEntity::EK_Delegating:
1158 case InitializedEntity::EK_BlockElement:
1159 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
1160 case InitializedEntity::EK_Binding:
1161 case InitializedEntity::EK_StmtExprResult:
1162 llvm_unreachable("unexpected braced scalar init");
1163 }
1164
1165 if (DiagID) {
1166 S.Diag(Braces.getBegin(), DiagID)
1167 << Entity.getType()->isSizelessBuiltinType() << Braces
1168 << FixItHint::CreateRemoval(Braces.getBegin())
1169 << FixItHint::CreateRemoval(Braces.getEnd());
1170 }
1171}
1172
1173/// Check whether the initializer \p IList (that was written with explicit
1174/// braces) can be used to initialize an object of type \p T.
1175///
1176/// This also fills in \p StructuredList with the fully-braced, desugared
1177/// form of the initialization.
1178void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
1179 InitListExpr *IList, QualType &T,
1180 InitListExpr *StructuredList,
1181 bool TopLevelObject) {
1182 unsigned Index = 0, StructuredIndex = 0;
1183 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
1184 Index, StructuredList, StructuredIndex, TopLevelObject);
1185 if (StructuredList) {
1186 QualType ExprTy = T;
1187 if (!ExprTy->isArrayType())
1188 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
1189 if (!VerifyOnly)
1190 IList->setType(ExprTy);
1191 StructuredList->setType(ExprTy);
1192 }
1193 if (hadError)
1194 return;
1195
1196 // Don't complain for incomplete types, since we'll get an error elsewhere.
1197 if (Index < IList->getNumInits() && !T->isIncompleteType()) {
1198 // We have leftover initializers
1199 bool ExtraInitsIsError = SemaRef.getLangOpts().CPlusPlus ||
1200 (SemaRef.getLangOpts().OpenCL && T->isVectorType());
1201 hadError = ExtraInitsIsError;
1202 if (VerifyOnly) {
1203 return;
1204 } else if (StructuredIndex == 1 &&
1205 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
1206 SIF_None) {
1207 unsigned DK =
1208 ExtraInitsIsError
1209 ? diag::err_excess_initializers_in_char_array_initializer
1210 : diag::ext_excess_initializers_in_char_array_initializer;
1211 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1212 << IList->getInit(Index)->getSourceRange();
1213 } else if (T->isSizelessBuiltinType()) {
1214 unsigned DK = ExtraInitsIsError
1215 ? diag::err_excess_initializers_for_sizeless_type
1216 : diag::ext_excess_initializers_for_sizeless_type;
1217 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1218 << T << IList->getInit(Index)->getSourceRange();
1219 } else {
1220 int initKind = T->isArrayType() ? 0 :
1221 T->isVectorType() ? 1 :
1222 T->isScalarType() ? 2 :
1223 T->isUnionType() ? 3 :
1224 4;
1225
1226 unsigned DK = ExtraInitsIsError ? diag::err_excess_initializers
1227 : diag::ext_excess_initializers;
1228 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1229 << initKind << IList->getInit(Index)->getSourceRange();
1230 }
1231 }
1232
1233 if (!VerifyOnly) {
1234 if (T->isScalarType() && IList->getNumInits() == 1 &&
1235 !isa<InitListExpr>(IList->getInit(0)))
1236 warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());
1237
1238 // Warn if this is a class type that won't be an aggregate in future
1239 // versions of C++.
1240 auto *CXXRD = T->getAsCXXRecordDecl();
1241 if (CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1242 // Don't warn if there's an equivalent default constructor that would be
1243 // used instead.
1244 bool HasEquivCtor = false;
1245 if (IList->getNumInits() == 0) {
1246 auto *CD = SemaRef.LookupDefaultConstructor(CXXRD);
1247 HasEquivCtor = CD && !CD->isDeleted();
1248 }
1249
1250 if (!HasEquivCtor) {
1251 SemaRef.Diag(IList->getBeginLoc(),
1252 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1253 << IList->getSourceRange() << T;
1254 }
1255 }
1256 }
1257}
1258
1259void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
1260 InitListExpr *IList,
1261 QualType &DeclType,
1262 bool SubobjectIsDesignatorContext,
1263 unsigned &Index,
1264 InitListExpr *StructuredList,
1265 unsigned &StructuredIndex,
1266 bool TopLevelObject) {
1267 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
1268 // Explicitly braced initializer for complex type can be real+imaginary
1269 // parts.
1270 CheckComplexType(Entity, IList, DeclType, Index,
1271 StructuredList, StructuredIndex);
1272 } else if (DeclType->isScalarType()) {
1273 CheckScalarType(Entity, IList, DeclType, Index,
1274 StructuredList, StructuredIndex);
1275 } else if (DeclType->isVectorType()) {
1276 CheckVectorType(Entity, IList, DeclType, Index,
1277 StructuredList, StructuredIndex);
1278 } else if (DeclType->isRecordType()) {
1279 assert(DeclType->isAggregateType() &&
1280 "non-aggregate records should be handed in CheckSubElementType");
1281 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
1282 auto Bases =
1283 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
1284 CXXRecordDecl::base_class_iterator());
1285 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1286 Bases = CXXRD->bases();
1287 CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
1288 SubobjectIsDesignatorContext, Index, StructuredList,
1289 StructuredIndex, TopLevelObject);
1290 } else if (DeclType->isArrayType()) {
1291 llvm::APSInt Zero(
1292 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
1293 false);
1294 CheckArrayType(Entity, IList, DeclType, Zero,
1295 SubobjectIsDesignatorContext, Index,
1296 StructuredList, StructuredIndex);
1297 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
1298 // This type is invalid, issue a diagnostic.
1299 ++Index;
1300 if (!VerifyOnly)
1301 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1302 << DeclType;
1303 hadError = true;
1304 } else if (DeclType->isReferenceType()) {
1305 CheckReferenceType(Entity, IList, DeclType, Index,
1306 StructuredList, StructuredIndex);
1307 } else if (DeclType->isObjCObjectType()) {
1308 if (!VerifyOnly)
1309 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_objc_class) << DeclType;
1310 hadError = true;
1311 } else if (DeclType->isOCLIntelSubgroupAVCType() ||
1312 DeclType->isSizelessBuiltinType()) {
1313 // Checks for scalar type are sufficient for these types too.
1314 CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1315 StructuredIndex);
1316 } else {
1317 if (!VerifyOnly)
1318 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1319 << DeclType;
1320 hadError = true;
1321 }
1322}
1323
1324void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
1325 InitListExpr *IList,
1326 QualType ElemType,
1327 unsigned &Index,
1328 InitListExpr *StructuredList,
1329 unsigned &StructuredIndex) {
1330 Expr *expr = IList->getInit(Index);
1331
1332 if (ElemType->isReferenceType())
1333 return CheckReferenceType(Entity, IList, ElemType, Index,
1334 StructuredList, StructuredIndex);
1335
1336 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
1337 if (SubInitList->getNumInits() == 1 &&
1338 IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
1339 SIF_None) {
1340 // FIXME: It would be more faithful and no less correct to include an
1341 // InitListExpr in the semantic form of the initializer list in this case.
1342 expr = SubInitList->getInit(0);
1343 }
1344 // Nested aggregate initialization and C++ initialization are handled later.
1345 } else if (isa<ImplicitValueInitExpr>(expr)) {
1346 // This happens during template instantiation when we see an InitListExpr
1347 // that we've already checked once.
1348 assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) &&
1349 "found implicit initialization for the wrong type");
1350 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1351 ++Index;
1352 return;
1353 }
1354
1355 if (SemaRef.getLangOpts().CPlusPlus || isa<InitListExpr>(expr)) {
1356 // C++ [dcl.init.aggr]p2:
1357 // Each member is copy-initialized from the corresponding
1358 // initializer-clause.
1359
1360 // FIXME: Better EqualLoc?
1361 InitializationKind Kind =
1362 InitializationKind::CreateCopy(expr->getBeginLoc(), SourceLocation());
1363
1364 // Vector elements can be initialized from other vectors in which case
1365 // we need initialization entity with a type of a vector (and not a vector
1366 // element!) initializing multiple vector elements.
1367 auto TmpEntity =
1368 (ElemType->isExtVectorType() && !Entity.getType()->isExtVectorType())
1369 ? InitializedEntity::InitializeTemporary(ElemType)
1370 : Entity;
1371
1372 InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
1373 /*TopLevelOfInitList*/ true);
1374
1375 // C++14 [dcl.init.aggr]p13:
1376 // If the assignment-expression can initialize a member, the member is
1377 // initialized. Otherwise [...] brace elision is assumed
1378 //
1379 // Brace elision is never performed if the element is not an
1380 // assignment-expression.
1381 if (Seq || isa<InitListExpr>(expr)) {
1382 if (!VerifyOnly) {
1383 ExprResult Result = Seq.Perform(SemaRef, TmpEntity, Kind, expr);
1384 if (Result.isInvalid())
1385 hadError = true;
1386
1387 UpdateStructuredListElement(StructuredList, StructuredIndex,
1388 Result.getAs<Expr>());
1389 } else if (!Seq) {
1390 hadError = true;
1391 } else if (StructuredList) {
1392 UpdateStructuredListElement(StructuredList, StructuredIndex,
1393 getDummyInit());
1394 }
1395 ++Index;
1396 return;
1397 }
1398
1399 // Fall through for subaggregate initialization
1400 } else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
1401 // FIXME: Need to handle atomic aggregate types with implicit init lists.
1402 return CheckScalarType(Entity, IList, ElemType, Index,
1403 StructuredList, StructuredIndex);
1404 } else if (const ArrayType *arrayType =
1405 SemaRef.Context.getAsArrayType(ElemType)) {
1406 // arrayType can be incomplete if we're initializing a flexible
1407 // array member. There's nothing we can do with the completed
1408 // type here, though.
1409
1410 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
1411 // FIXME: Should we do this checking in verify-only mode?
1412 if (!VerifyOnly)
1413 CheckStringInit(expr, ElemType, arrayType, SemaRef);
1414 if (StructuredList)
1415 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1416 ++Index;
1417 return;
1418 }
1419
1420 // Fall through for subaggregate initialization.
1421
1422 } else {
1423 assert((ElemType->isRecordType() || ElemType->isVectorType() ||
1424 ElemType->isOpenCLSpecificType()) && "Unexpected type");
1425
1426 // C99 6.7.8p13:
1427 //
1428 // The initializer for a structure or union object that has
1429 // automatic storage duration shall be either an initializer
1430 // list as described below, or a single expression that has
1431 // compatible structure or union type. In the latter case, the
1432 // initial value of the object, including unnamed members, is
1433 // that of the expression.
1434 ExprResult ExprRes = expr;
1435 if (SemaRef.CheckSingleAssignmentConstraints(
1436 ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
1437 if (ExprRes.isInvalid())
1438 hadError = true;
1439 else {
1440 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
1441 if (ExprRes.isInvalid())
1442 hadError = true;
1443 }
1444 UpdateStructuredListElement(StructuredList, StructuredIndex,
1445 ExprRes.getAs<Expr>());
1446 ++Index;
1447 return;
1448 }
1449 ExprRes.get();
1450 // Fall through for subaggregate initialization
1451 }
1452
1453 // C++ [dcl.init.aggr]p12:
1454 //
1455 // [...] Otherwise, if the member is itself a non-empty
1456 // subaggregate, brace elision is assumed and the initializer is
1457 // considered for the initialization of the first member of
1458 // the subaggregate.
1459 // OpenCL vector initializer is handled elsewhere.
1460 if ((!SemaRef.getLangOpts().OpenCL && ElemType->isVectorType()) ||
1461 ElemType->isAggregateType()) {
1462 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
1463 StructuredIndex);
1464 ++StructuredIndex;
1465 } else {
1466 if (!VerifyOnly) {
1467 // We cannot initialize this element, so let PerformCopyInitialization
1468 // produce the appropriate diagnostic. We already checked that this
1469 // initialization will fail.
1470 ExprResult Copy =
1471 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
1472 /*TopLevelOfInitList=*/true);
1473 (void)Copy;
1474 assert(Copy.isInvalid() &&
1475 "expected non-aggregate initialization to fail");
1476 }
1477 hadError = true;
1478 ++Index;
1479 ++StructuredIndex;
1480 }
1481}
1482
1483void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
1484 InitListExpr *IList, QualType DeclType,
1485 unsigned &Index,
1486 InitListExpr *StructuredList,
1487 unsigned &StructuredIndex) {
1488 assert(Index == 0 && "Index in explicit init list must be zero");
1489
1490 // As an extension, clang supports complex initializers, which initialize
1491 // a complex number component-wise. When an explicit initializer list for
1492 // a complex number contains two two initializers, this extension kicks in:
1493 // it exepcts the initializer list to contain two elements convertible to
1494 // the element type of the complex type. The first element initializes
1495 // the real part, and the second element intitializes the imaginary part.
1496
1497 if (IList->getNumInits() != 2)
1498 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1499 StructuredIndex);
1500
1501 // This is an extension in C. (The builtin _Complex type does not exist
1502 // in the C++ standard.)
1503 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
1504 SemaRef.Diag(IList->getBeginLoc(), diag::ext_complex_component_init)
1505 << IList->getSourceRange();
1506
1507 // Initialize the complex number.
1508 QualType elementType = DeclType->castAs<ComplexType>()->getElementType();
1509 InitializedEntity ElementEntity =
1510 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1511
1512 for (unsigned i = 0; i < 2; ++i) {
1513 ElementEntity.setElementIndex(Index);
1514 CheckSubElementType(ElementEntity, IList, elementType, Index,
1515 StructuredList, StructuredIndex);
1516 }
1517}
1518
1519void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
1520 InitListExpr *IList, QualType DeclType,
1521 unsigned &Index,
1522 InitListExpr *StructuredList,
1523 unsigned &StructuredIndex) {
1524 if (Index >= IList->getNumInits()) {
1525 if (!VerifyOnly) {
1526 if (DeclType->isSizelessBuiltinType())
1527 SemaRef.Diag(IList->getBeginLoc(),
1528 SemaRef.getLangOpts().CPlusPlus11
1529 ? diag::warn_cxx98_compat_empty_sizeless_initializer
1530 : diag::err_empty_sizeless_initializer)
1531 << DeclType << IList->getSourceRange();
1532 else
1533 SemaRef.Diag(IList->getBeginLoc(),
1534 SemaRef.getLangOpts().CPlusPlus11
1535 ? diag::warn_cxx98_compat_empty_scalar_initializer
1536 : diag::err_empty_scalar_initializer)
1537 << IList->getSourceRange();
1538 }
1539 hadError = !SemaRef.getLangOpts().CPlusPlus11;
1540 ++Index;
1541 ++StructuredIndex;
1542 return;
1543 }
1544
1545 Expr *expr = IList->getInit(Index);
1546 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
1547 // FIXME: This is invalid, and accepting it causes overload resolution
1548 // to pick the wrong overload in some corner cases.
1549 if (!VerifyOnly)
1550 SemaRef.Diag(SubIList->getBeginLoc(), diag::ext_many_braces_around_init)
1551 << DeclType->isSizelessBuiltinType() << SubIList->getSourceRange();
1552
1553 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
1554 StructuredIndex);
1555 return;
1556 } else if (isa<DesignatedInitExpr>(expr)) {
1557 if (!VerifyOnly)
1558 SemaRef.Diag(expr->getBeginLoc(),
1559 diag::err_designator_for_scalar_or_sizeless_init)
1560 << DeclType->isSizelessBuiltinType() << DeclType
1561 << expr->getSourceRange();
1562 hadError = true;
1563 ++Index;
1564 ++StructuredIndex;
1565 return;
1566 }
1567
1568 ExprResult Result;
1569 if (VerifyOnly) {
1570 if (SemaRef.CanPerformCopyInitialization(Entity, expr))
1571 Result = getDummyInit();
1572 else
1573 Result = ExprError();
1574 } else {
1575 Result =
1576 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1577 /*TopLevelOfInitList=*/true);
1578 }
1579
1580 Expr *ResultExpr = nullptr;
1581
1582 if (Result.isInvalid())
1583 hadError = true; // types weren't compatible.
1584 else {
1585 ResultExpr = Result.getAs<Expr>();
1586
1587 if (ResultExpr != expr && !VerifyOnly) {
1588 // The type was promoted, update initializer list.
1589 // FIXME: Why are we updating the syntactic init list?
1590 IList->setInit(Index, ResultExpr);
1591 }
1592 }
1593 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1594 ++Index;
1595}
1596
1597void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
1598 InitListExpr *IList, QualType DeclType,
1599 unsigned &Index,
1600 InitListExpr *StructuredList,
1601 unsigned &StructuredIndex) {
1602 if (Index >= IList->getNumInits()) {
1603 // FIXME: It would be wonderful if we could point at the actual member. In
1604 // general, it would be useful to pass location information down the stack,
1605 // so that we know the location (or decl) of the "current object" being
1606 // initialized.
1607 if (!VerifyOnly)
1608 SemaRef.Diag(IList->getBeginLoc(),
1609 diag::err_init_reference_member_uninitialized)
1610 << DeclType << IList->getSourceRange();
1611 hadError = true;
1612 ++Index;
1613 ++StructuredIndex;
1614 return;
1615 }
1616
1617 Expr *expr = IList->getInit(Index);
1618 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
1619 if (!VerifyOnly)
1620 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_non_aggr_init_list)
1621 << DeclType << IList->getSourceRange();
1622 hadError = true;
1623 ++Index;
1624 ++StructuredIndex;
1625 return;
1626 }
1627
1628 ExprResult Result;
1629 if (VerifyOnly) {
1630 if (SemaRef.CanPerformCopyInitialization(Entity,expr))
1631 Result = getDummyInit();
1632 else
1633 Result = ExprError();
1634 } else {
1635 Result =
1636 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1637 /*TopLevelOfInitList=*/true);
1638 }
1639
1640 if (Result.isInvalid())
1641 hadError = true;
1642
1643 expr = Result.getAs<Expr>();
1644 // FIXME: Why are we updating the syntactic init list?
1645 if (!VerifyOnly && expr)
1646 IList->setInit(Index, expr);
1647
1648 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1649 ++Index;
1650}
1651
1652void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
1653 InitListExpr *IList, QualType DeclType,
1654 unsigned &Index,
1655 InitListExpr *StructuredList,
1656 unsigned &StructuredIndex) {
1657 const VectorType *VT = DeclType->castAs<VectorType>();
1658 unsigned maxElements = VT->getNumElements();
1659 unsigned numEltsInit = 0;
1660 QualType elementType = VT->getElementType();
1661
1662 if (Index >= IList->getNumInits()) {
1663 // Make sure the element type can be value-initialized.
1664 CheckEmptyInitializable(
1665 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1666 IList->getEndLoc());
1667 return;
1668 }
1669
1670 if (!SemaRef.getLangOpts().OpenCL) {
1671 // If the initializing element is a vector, try to copy-initialize
1672 // instead of breaking it apart (which is doomed to failure anyway).
1673 Expr *Init = IList->getInit(Index);
1674 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
1675 ExprResult Result;
1676 if (VerifyOnly) {
1677 if (SemaRef.CanPerformCopyInitialization(Entity, Init))
1678 Result = getDummyInit();
1679 else
1680 Result = ExprError();
1681 } else {
1682 Result =
1683 SemaRef.PerformCopyInitialization(Entity, Init->getBeginLoc(), Init,
1684 /*TopLevelOfInitList=*/true);
1685 }
1686
1687 Expr *ResultExpr = nullptr;
1688 if (Result.isInvalid())
1689 hadError = true; // types weren't compatible.
1690 else {
1691 ResultExpr = Result.getAs<Expr>();
1692
1693 if (ResultExpr != Init && !VerifyOnly) {
1694 // The type was promoted, update initializer list.
1695 // FIXME: Why are we updating the syntactic init list?
1696 IList->setInit(Index, ResultExpr);
1697 }
1698 }
1699 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1700 ++Index;
1701 return;
1702 }
1703
1704 InitializedEntity ElementEntity =
1705 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1706
1707 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
1708 // Don't attempt to go past the end of the init list
1709 if (Index >= IList->getNumInits()) {
1710 CheckEmptyInitializable(ElementEntity, IList->getEndLoc());
1711 break;
1712 }
1713
1714 ElementEntity.setElementIndex(Index);
1715 CheckSubElementType(ElementEntity, IList, elementType, Index,
1716 StructuredList, StructuredIndex);
1717 }
1718
1719 if (VerifyOnly)
1720 return;
1721
1722 bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
1723 const VectorType *T = Entity.getType()->castAs<VectorType>();
1724 if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
1725 T->getVectorKind() == VectorType::NeonPolyVector)) {
1726 // The ability to use vector initializer lists is a GNU vector extension
1727 // and is unrelated to the NEON intrinsics in arm_neon.h. On little
1728 // endian machines it works fine, however on big endian machines it
1729 // exhibits surprising behaviour:
1730 //
1731 // uint32x2_t x = {42, 64};
1732 // return vget_lane_u32(x, 0); // Will return 64.
1733 //
1734 // Because of this, explicitly call out that it is non-portable.
1735 //
1736 SemaRef.Diag(IList->getBeginLoc(),
1737 diag::warn_neon_vector_initializer_non_portable);
1738
1739 const char *typeCode;
1740 unsigned typeSize = SemaRef.Context.getTypeSize(elementType);
1741
1742 if (elementType->isFloatingType())
1743 typeCode = "f";
1744 else if (elementType->isSignedIntegerType())
1745 typeCode = "s";
1746 else if (elementType->isUnsignedIntegerType())
1747 typeCode = "u";
1748 else
1749 llvm_unreachable("Invalid element type!");
1750
1751 SemaRef.Diag(IList->getBeginLoc(),
1752 SemaRef.Context.getTypeSize(VT) > 64
1753 ? diag::note_neon_vector_initializer_non_portable_q
1754 : diag::note_neon_vector_initializer_non_portable)
1755 << typeCode << typeSize;
1756 }
1757
1758 return;
1759 }
1760
1761 InitializedEntity ElementEntity =
1762 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1763
1764 // OpenCL initializers allows vectors to be constructed from vectors.
1765 for (unsigned i = 0; i < maxElements; ++i) {
1766 // Don't attempt to go past the end of the init list
1767 if (Index >= IList->getNumInits())
1768 break;
1769
1770 ElementEntity.setElementIndex(Index);
1771
1772 QualType IType = IList->getInit(Index)->getType();
1773 if (!IType->isVectorType()) {
1774 CheckSubElementType(ElementEntity, IList, elementType, Index,
1775 StructuredList, StructuredIndex);
1776 ++numEltsInit;
1777 } else {
1778 QualType VecType;
1779 const VectorType *IVT = IType->castAs<VectorType>();
1780 unsigned numIElts = IVT->getNumElements();
1781
1782 if (IType->isExtVectorType())
1783 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
1784 else
1785 VecType = SemaRef.Context.getVectorType(elementType, numIElts,
1786 IVT->getVectorKind());
1787 CheckSubElementType(ElementEntity, IList, VecType, Index,
1788 StructuredList, StructuredIndex);
1789 numEltsInit += numIElts;
1790 }
1791 }
1792
1793 // OpenCL requires all elements to be initialized.
1794 if (numEltsInit != maxElements) {
1795 if (!VerifyOnly)
1796 SemaRef.Diag(IList->getBeginLoc(),
1797 diag::err_vector_incorrect_num_initializers)
1798 << (numEltsInit < maxElements) << maxElements << numEltsInit;
1799 hadError = true;
1800 }
1801}
1802
1803/// Check if the type of a class element has an accessible destructor, and marks
1804/// it referenced. Returns true if we shouldn't form a reference to the
1805/// destructor.
1806///
1807/// Aggregate initialization requires a class element's destructor be
1808/// accessible per 11.6.1 [dcl.init.aggr]:
1809///
1810/// The destructor for each element of class type is potentially invoked
1811/// (15.4 [class.dtor]) from the context where the aggregate initialization
1812/// occurs.
1813static bool checkDestructorReference(QualType ElementType, SourceLocation Loc,
1814 Sema &SemaRef) {
1815 auto *CXXRD = ElementType->getAsCXXRecordDecl();
1816 if (!CXXRD)
1817 return false;
1818
1819 CXXDestructorDecl *Destructor = SemaRef.LookupDestructor(CXXRD);
1820 SemaRef.CheckDestructorAccess(Loc, Destructor,
1821 SemaRef.PDiag(diag::err_access_dtor_temp)
1822 << ElementType);
1823 SemaRef.MarkFunctionReferenced(Loc, Destructor);
1824 return SemaRef.DiagnoseUseOfDecl(Destructor, Loc);
1825}
1826
1827void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
1828 InitListExpr *IList, QualType &DeclType,
1829 llvm::APSInt elementIndex,
1830 bool SubobjectIsDesignatorContext,
1831 unsigned &Index,
1832 InitListExpr *StructuredList,
1833 unsigned &StructuredIndex) {
1834 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);
1835
1836 if (!VerifyOnly) {
1837 if (checkDestructorReference(arrayType->getElementType(),
1838 IList->getEndLoc(), SemaRef)) {
1839 hadError = true;
1840 return;
1841 }
1842 }
1843
1844 // Check for the special-case of initializing an array with a string.
1845 if (Index < IList->getNumInits()) {
1846 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
1847 SIF_None) {
1848 // We place the string literal directly into the resulting
1849 // initializer list. This is the only place where the structure
1850 // of the structured initializer list doesn't match exactly,
1851 // because doing so would involve allocating one character
1852 // constant for each string.
1853 // FIXME: Should we do these checks in verify-only mode too?
1854 if (!VerifyOnly)
1855 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
1856 if (StructuredList) {
1857 UpdateStructuredListElement(StructuredList, StructuredIndex,
1858 IList->getInit(Index));
1859 StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
1860 }
1861 ++Index;
1862 return;
1863 }
1864 }
1865 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
1866 // Check for VLAs; in standard C it would be possible to check this
1867 // earlier, but I don't know where clang accepts VLAs (gcc accepts
1868 // them in all sorts of strange places).
1869 if (!VerifyOnly)
1870 SemaRef.Diag(VAT->getSizeExpr()->getBeginLoc(),
1871 diag::err_variable_object_no_init)
1872 << VAT->getSizeExpr()->getSourceRange();
1873 hadError = true;
1874 ++Index;
1875 ++StructuredIndex;
1876 return;
1877 }
1878
1879 // We might know the maximum number of elements in advance.
1880 llvm::APSInt maxElements(elementIndex.getBitWidth(),
1881 elementIndex.isUnsigned());
1882 bool maxElementsKnown = false;
1883 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
1884 maxElements = CAT->getSize();
1885 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
1886 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1887 maxElementsKnown = true;
1888 }
1889
1890 QualType elementType = arrayType->getElementType();
1891 while (Index < IList->getNumInits()) {
1892 Expr *Init = IList->getInit(Index);
1893 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
1894 // If we're not the subobject that matches up with the '{' for
1895 // the designator, we shouldn't be handling the
1896 // designator. Return immediately.
1897 if (!SubobjectIsDesignatorContext)
1898 return;
1899
1900 // Handle this designated initializer. elementIndex will be
1901 // updated to be the next array element we'll initialize.
1902 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
1903 DeclType, nullptr, &elementIndex, Index,
1904 StructuredList, StructuredIndex, true,
1905 false)) {
1906 hadError = true;
1907 continue;
1908 }
1909
1910 if (elementIndex.getBitWidth() > maxElements.getBitWidth())
1911 maxElements = maxElements.extend(elementIndex.getBitWidth());
1912 else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
1913 elementIndex = elementIndex.extend(maxElements.getBitWidth());
1914 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1915
1916 // If the array is of incomplete type, keep track of the number of
1917 // elements in the initializer.
1918 if (!maxElementsKnown && elementIndex > maxElements)
1919 maxElements = elementIndex;
1920
1921 continue;
1922 }
1923
1924 // If we know the maximum number of elements, and we've already
1925 // hit it, stop consuming elements in the initializer list.
1926 if (maxElementsKnown && elementIndex == maxElements)
1927 break;
1928
1929 InitializedEntity ElementEntity =
1930 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
1931 Entity);
1932 // Check this element.
1933 CheckSubElementType(ElementEntity, IList, elementType, Index,
1934 StructuredList, StructuredIndex);
1935 ++elementIndex;
1936
1937 // If the array is of incomplete type, keep track of the number of
1938 // elements in the initializer.
1939 if (!maxElementsKnown && elementIndex > maxElements)
1940 maxElements = elementIndex;
1941 }
1942 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
1943 // If this is an incomplete array type, the actual type needs to
1944 // be calculated here.
1945 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
1946 if (maxElements == Zero && !Entity.isVariableLengthArrayNew()) {
1947 // Sizing an array implicitly to zero is not allowed by ISO C,
1948 // but is supported by GNU.
1949 SemaRef.Diag(IList->getBeginLoc(), diag::ext_typecheck_zero_array_size);
1950 }
1951
1952 DeclType = SemaRef.Context.getConstantArrayType(
1953 elementType, maxElements, nullptr, ArrayType::Normal, 0);
1954 }
1955 if (!hadError) {
1956 // If there are any members of the array that get value-initialized, check
1957 // that is possible. That happens if we know the bound and don't have
1958 // enough elements, or if we're performing an array new with an unknown
1959 // bound.
1960 if ((maxElementsKnown && elementIndex < maxElements) ||
1961 Entity.isVariableLengthArrayNew())
1962 CheckEmptyInitializable(
1963 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1964 IList->getEndLoc());
1965 }
1966}
1967
1968bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
1969 Expr *InitExpr,
1970 FieldDecl *Field,
1971 bool TopLevelObject) {
1972 // Handle GNU flexible array initializers.
1973 unsigned FlexArrayDiag;
1974 if (isa<InitListExpr>(InitExpr) &&
1975 cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
1976 // Empty flexible array init always allowed as an extension
1977 FlexArrayDiag = diag::ext_flexible_array_init;
1978 } else if (SemaRef.getLangOpts().CPlusPlus) {
1979 // Disallow flexible array init in C++; it is not required for gcc
1980 // compatibility, and it needs work to IRGen correctly in general.
1981 FlexArrayDiag = diag::err_flexible_array_init;
1982 } else if (!TopLevelObject) {
1983 // Disallow flexible array init on non-top-level object
1984 FlexArrayDiag = diag::err_flexible_array_init;
1985 } else if (Entity.getKind() != InitializedEntity::EK_Variable) {
1986 // Disallow flexible array init on anything which is not a variable.
1987 FlexArrayDiag = diag::err_flexible_array_init;
1988 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
1989 // Disallow flexible array init on local variables.
1990 FlexArrayDiag = diag::err_flexible_array_init;
1991 } else {
1992 // Allow other cases.
1993 FlexArrayDiag = diag::ext_flexible_array_init;
1994 }
1995
1996 if (!VerifyOnly) {
1997 SemaRef.Diag(InitExpr->getBeginLoc(), FlexArrayDiag)
1998 << InitExpr->getBeginLoc();
1999 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2000 << Field;
2001 }
2002
2003 return FlexArrayDiag != diag::ext_flexible_array_init;
2004}
2005
2006void InitListChecker::CheckStructUnionTypes(
2007 const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
2008 CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
2009 bool SubobjectIsDesignatorContext, unsigned &Index,
2010 InitListExpr *StructuredList, unsigned &StructuredIndex,
2011 bool TopLevelObject) {
2012 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
2013
2014 // If the record is invalid, some of it's members are invalid. To avoid
2015 // confusion, we forgo checking the intializer for the entire record.
2016 if (structDecl->isInvalidDecl()) {
2017 // Assume it was supposed to consume a single initializer.
2018 ++Index;
2019 hadError = true;
2020 return;
2021 }
2022
2023 if (DeclType->isUnionType() && IList->getNumInits() == 0) {
2024 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2025
2026 if (!VerifyOnly)
2027 for (FieldDecl *FD : RD->fields()) {
2028 QualType ET = SemaRef.Context.getBaseElementType(FD->getType());
2029 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2030 hadError = true;
2031 return;
2032 }
2033 }
2034
2035 // If there's a default initializer, use it.
2036 if (isa<CXXRecordDecl>(RD) &&
2037 cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
2038 if (!StructuredList)
2039 return;
2040 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2041 Field != FieldEnd; ++Field) {
2042 if (Field->hasInClassInitializer()) {
2043 StructuredList->setInitializedFieldInUnion(*Field);
2044 // FIXME: Actually build a CXXDefaultInitExpr?
2045 return;
2046 }
2047 }
2048 }
2049
2050 // Value-initialize the first member of the union that isn't an unnamed
2051 // bitfield.
2052 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2053 Field != FieldEnd; ++Field) {
2054 if (!Field->isUnnamedBitfield()) {
2055 CheckEmptyInitializable(
2056 InitializedEntity::InitializeMember(*Field, &Entity),
2057 IList->getEndLoc());
2058 if (StructuredList)
2059 StructuredList->setInitializedFieldInUnion(*Field);
2060 break;
2061 }
2062 }
2063 return;
2064 }
2065
2066 bool InitializedSomething = false;
2067
2068 // If we have any base classes, they are initialized prior to the fields.
2069 for (auto &Base : Bases) {
2070 Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;
2071
2072 // Designated inits always initialize fields, so if we see one, all
2073 // remaining base classes have no explicit initializer.
2074 if (Init && isa<DesignatedInitExpr>(Init))
2075 Init = nullptr;
2076
2077 SourceLocation InitLoc = Init ? Init->getBeginLoc() : IList->getEndLoc();
2078 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
2079 SemaRef.Context, &Base, false, &Entity);
2080 if (Init) {
2081 CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
2082 StructuredList, StructuredIndex);
2083 InitializedSomething = true;
2084 } else {
2085 CheckEmptyInitializable(BaseEntity, InitLoc);
2086 }
2087
2088 if (!VerifyOnly)
2089 if (checkDestructorReference(Base.getType(), InitLoc, SemaRef)) {
2090 hadError = true;
2091 return;
2092 }
2093 }
2094
2095 // If structDecl is a forward declaration, this loop won't do
2096 // anything except look at designated initializers; That's okay,
2097 // because an error should get printed out elsewhere. It might be
2098 // worthwhile to skip over the rest of the initializer, though.
2099 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2100 RecordDecl::field_iterator FieldEnd = RD->field_end();
2101 bool CheckForMissingFields =
2102 !IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
2103 bool HasDesignatedInit = false;
2104
2105 while (Index < IList->getNumInits()) {
2106 Expr *Init = IList->getInit(Index);
2107 SourceLocation InitLoc = Init->getBeginLoc();
2108
2109 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
2110 // If we're not the subobject that matches up with the '{' for
2111 // the designator, we shouldn't be handling the
2112 // designator. Return immediately.
2113 if (!SubobjectIsDesignatorContext)
2114 return;
2115
2116 HasDesignatedInit = true;
2117
2118 // Handle this designated initializer. Field will be updated to
2119 // the next field that we'll be initializing.
2120 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
2121 DeclType, &Field, nullptr, Index,
2122 StructuredList, StructuredIndex,
2123 true, TopLevelObject))
2124 hadError = true;
2125 else if (!VerifyOnly) {
2126 // Find the field named by the designated initializer.
2127 RecordDecl::field_iterator F = RD->field_begin();
2128 while (std::next(F) != Field)
2129 ++F;
2130 QualType ET = SemaRef.Context.getBaseElementType(F->getType());
2131 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2132 hadError = true;
2133 return;
2134 }
2135 }
2136
2137 InitializedSomething = true;
2138
2139 // Disable check for missing fields when designators are used.
2140 // This matches gcc behaviour.
2141 CheckForMissingFields = false;
2142 continue;
2143 }
2144
2145 if (Field == FieldEnd) {
2146 // We've run out of fields. We're done.
2147 break;
2148 }
2149
2150 // We've already initialized a member of a union. We're done.
2151 if (InitializedSomething && DeclType->isUnionType())
2152 break;
2153
2154 // If we've hit the flexible array member at the end, we're done.
2155 if (Field->getType()->isIncompleteArrayType())
2156 break;
2157
2158 if (Field->isUnnamedBitfield()) {
2159 // Don't initialize unnamed bitfields, e.g. "int : 20;"
2160 ++Field;
2161 continue;
2162 }
2163
2164 // Make sure we can use this declaration.
2165 bool InvalidUse;
2166 if (VerifyOnly)
2167 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2168 else
2169 InvalidUse = SemaRef.DiagnoseUseOfDecl(
2170 *Field, IList->getInit(Index)->getBeginLoc());
2171 if (InvalidUse) {
2172 ++Index;
2173 ++Field;
2174 hadError = true;
2175 continue;
2176 }
2177
2178 if (!VerifyOnly) {
2179 QualType ET = SemaRef.Context.getBaseElementType(Field->getType());
2180 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2181 hadError = true;
2182 return;
2183 }
2184 }
2185
2186 InitializedEntity MemberEntity =
2187 InitializedEntity::InitializeMember(*Field, &Entity);
2188 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2189 StructuredList, StructuredIndex);
2190 InitializedSomething = true;
2191
2192 if (DeclType->isUnionType() && StructuredList) {
2193 // Initialize the first field within the union.
2194 StructuredList->setInitializedFieldInUnion(*Field);
2195 }
2196
2197 ++Field;
2198 }
2199
2200 // Emit warnings for missing struct field initializers.
2201 if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
2202 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
2203 !DeclType->isUnionType()) {
2204 // It is possible we have one or more unnamed bitfields remaining.
2205 // Find first (if any) named field and emit warning.
2206 for (RecordDecl::field_iterator it = Field, end = RD->field_end();
2207 it != end; ++it) {
2208 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
2209 SemaRef.Diag(IList->getSourceRange().getEnd(),
2210 diag::warn_missing_field_initializers) << *it;
2211 break;
2212 }
2213 }
2214 }
2215
2216 // Check that any remaining fields can be value-initialized if we're not
2217 // building a structured list. (If we are, we'll check this later.)
2218 if (!StructuredList && Field != FieldEnd && !DeclType->isUnionType() &&
2219 !Field->getType()->isIncompleteArrayType()) {
2220 for (; Field != FieldEnd && !hadError; ++Field) {
2221 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
2222 CheckEmptyInitializable(
2223 InitializedEntity::InitializeMember(*Field, &Entity),
2224 IList->getEndLoc());
2225 }
2226 }
2227
2228 // Check that the types of the remaining fields have accessible destructors.
2229 if (!VerifyOnly) {
2230 // If the initializer expression has a designated initializer, check the
2231 // elements for which a designated initializer is not provided too.
2232 RecordDecl::field_iterator I = HasDesignatedInit ? RD->field_begin()
2233 : Field;
2234 for (RecordDecl::field_iterator E = RD->field_end(); I != E; ++I) {
2235 QualType ET = SemaRef.Context.getBaseElementType(I->getType());
2236 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2237 hadError = true;
2238 return;
2239 }
2240 }
2241 }
2242
2243 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
2244 Index >= IList->getNumInits())
2245 return;
2246
2247 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
2248 TopLevelObject)) {
2249 hadError = true;
2250 ++Index;
2251 return;
2252 }
2253
2254 InitializedEntity MemberEntity =
2255 InitializedEntity::InitializeMember(*Field, &Entity);
2256
2257 if (isa<InitListExpr>(IList->getInit(Index)))
2258 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2259 StructuredList, StructuredIndex);
2260 else
2261 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
2262 StructuredList, StructuredIndex);
2263}
2264
2265/// Expand a field designator that refers to a member of an
2266/// anonymous struct or union into a series of field designators that
2267/// refers to the field within the appropriate subobject.
2268///
2269static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
2270 DesignatedInitExpr *DIE,
2271 unsigned DesigIdx,
2272 IndirectFieldDecl *IndirectField) {
2273 typedef DesignatedInitExpr::Designator Designator;
2274
2275 // Build the replacement designators.
2276 SmallVector<Designator, 4> Replacements;
2277 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
2278 PE = IndirectField->chain_end(); PI != PE; ++PI) {
2279 if (PI + 1 == PE)
2280 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2281 DIE->getDesignator(DesigIdx)->getDotLoc(),
2282 DIE->getDesignator(DesigIdx)->getFieldLoc()));
2283 else
2284 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2285 SourceLocation(), SourceLocation()));
2286 assert(isa<FieldDecl>(*PI));
2287 Replacements.back().setField(cast<FieldDecl>(*PI));
2288 }
2289
2290 // Expand the current designator into the set of replacement
2291 // designators, so we have a full subobject path down to where the
2292 // member of the anonymous struct/union is actually stored.
2293 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
2294 &Replacements[0] + Replacements.size());
2295}
2296
2297static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
2298 DesignatedInitExpr *DIE) {
2299 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
2300 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
2301 for (unsigned I = 0; I < NumIndexExprs; ++I)
2302 IndexExprs[I] = DIE->getSubExpr(I + 1);
2303 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
2304 IndexExprs,
2305 DIE->getEqualOrColonLoc(),
2306 DIE->usesGNUSyntax(), DIE->getInit());
2307}
2308
2309namespace {
2310
2311// Callback to only accept typo corrections that are for field members of
2312// the given struct or union.
2313class FieldInitializerValidatorCCC final : public CorrectionCandidateCallback {
2314 public:
2315 explicit FieldInitializerValidatorCCC(RecordDecl *RD)
2316 : Record(RD) {}
2317
2318 bool ValidateCandidate(const TypoCorrection &candidate) override {
2319 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
2320 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
2321 }
2322
2323 std::unique_ptr<CorrectionCandidateCallback> clone() override {
2324 return std::make_unique<FieldInitializerValidatorCCC>(*this);
2325 }
2326
2327 private:
2328 RecordDecl *Record;
2329};
2330
2331} // end anonymous namespace
2332
2333/// Check the well-formedness of a C99 designated initializer.
2334///
2335/// Determines whether the designated initializer @p DIE, which
2336/// resides at the given @p Index within the initializer list @p
2337/// IList, is well-formed for a current object of type @p DeclType
2338/// (C99 6.7.8). The actual subobject that this designator refers to
2339/// within the current subobject is returned in either
2340/// @p NextField or @p NextElementIndex (whichever is appropriate).
2341///
2342/// @param IList The initializer list in which this designated
2343/// initializer occurs.
2344///
2345/// @param DIE The designated initializer expression.
2346///
2347/// @param DesigIdx The index of the current designator.
2348///
2349/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
2350/// into which the designation in @p DIE should refer.
2351///
2352/// @param NextField If non-NULL and the first designator in @p DIE is
2353/// a field, this will be set to the field declaration corresponding
2354/// to the field named by the designator. On input, this is expected to be
2355/// the next field that would be initialized in the absence of designation,
2356/// if the complete object being initialized is a struct.
2357///
2358/// @param NextElementIndex If non-NULL and the first designator in @p
2359/// DIE is an array designator or GNU array-range designator, this
2360/// will be set to the last index initialized by this designator.
2361///
2362/// @param Index Index into @p IList where the designated initializer
2363/// @p DIE occurs.
2364///
2365/// @param StructuredList The initializer list expression that
2366/// describes all of the subobject initializers in the order they'll
2367/// actually be initialized.
2368///
2369/// @returns true if there was an error, false otherwise.
2370bool
2371InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
2372 InitListExpr *IList,
2373 DesignatedInitExpr *DIE,
2374 unsigned DesigIdx,
2375 QualType &CurrentObjectType,
2376 RecordDecl::field_iterator *NextField,
2377 llvm::APSInt *NextElementIndex,
2378 unsigned &Index,
2379 InitListExpr *StructuredList,
2380 unsigned &StructuredIndex,
2381 bool FinishSubobjectInit,
2382 bool TopLevelObject) {
2383 if (DesigIdx == DIE->size()) {
2384 // C++20 designated initialization can result in direct-list-initialization
2385 // of the designated subobject. This is the only way that we can end up
2386 // performing direct initialization as part of aggregate initialization, so
2387 // it needs special handling.
2388 if (DIE->isDirectInit()) {
2389 Expr *Init = DIE->getInit();
2390 assert(isa<InitListExpr>(Init) &&
2391 "designator result in direct non-list initialization?");
2392 InitializationKind Kind = InitializationKind::CreateDirectList(
2393 DIE->getBeginLoc(), Init->getBeginLoc(), Init->getEndLoc());
2394 InitializationSequence Seq(SemaRef, Entity, Kind, Init,
2395 /*TopLevelOfInitList*/ true);
2396 if (StructuredList) {
2397 ExprResult Result = VerifyOnly
2398 ? getDummyInit()
2399 : Seq.Perform(SemaRef, Entity, Kind, Init);
2400 UpdateStructuredListElement(StructuredList, StructuredIndex,
2401 Result.get());
2402 }
2403 ++Index;
2404 return !Seq;
2405 }
2406
2407 // Check the actual initialization for the designated object type.
2408 bool prevHadError = hadError;
2409
2410 // Temporarily remove the designator expression from the
2411 // initializer list that the child calls see, so that we don't try
2412 // to re-process the designator.
2413 unsigned OldIndex = Index;
2414 IList->setInit(OldIndex, DIE->getInit());
2415
2416 CheckSubElementType(Entity, IList, CurrentObjectType, Index,
2417 StructuredList, StructuredIndex);
2418
2419 // Restore the designated initializer expression in the syntactic
2420 // form of the initializer list.
2421 if (IList->getInit(OldIndex) != DIE->getInit())
2422 DIE->setInit(IList->getInit(OldIndex));
2423 IList->setInit(OldIndex, DIE);
2424
2425 return hadError && !prevHadError;
2426 }
2427
2428 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
2429 bool IsFirstDesignator = (DesigIdx == 0);
2430 if (IsFirstDesignator ? FullyStructuredList : StructuredList) {
2431 // Determine the structural initializer list that corresponds to the
2432 // current subobject.
2433 if (IsFirstDesignator)
2434 StructuredList = FullyStructuredList;
2435 else {
2436 Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
2437 StructuredList->getInit(StructuredIndex) : nullptr;
2438 if (!ExistingInit && StructuredList->hasArrayFiller())
2439 ExistingInit = StructuredList->getArrayFiller();
2440
2441 if (!ExistingInit)
2442 StructuredList = getStructuredSubobjectInit(
2443 IList, Index, CurrentObjectType, StructuredList, StructuredIndex,
2444 SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2445 else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
2446 StructuredList = Result;
2447 else {
2448 // We are creating an initializer list that initializes the
2449 // subobjects of the current object, but there was already an
2450 // initialization that completely initialized the current
2451 // subobject, e.g., by a compound literal:
2452 //
2453 // struct X { int a, b; };
2454 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
2455 //
2456 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
2457 // designated initializer re-initializes only its current object
2458 // subobject [0].b.
2459 diagnoseInitOverride(ExistingInit,
2460 SourceRange(D->getBeginLoc(), DIE->getEndLoc()),
2461 /*FullyOverwritten=*/false);
2462
2463 if (!VerifyOnly) {
2464 if (DesignatedInitUpdateExpr *E =
2465 dyn_cast<DesignatedInitUpdateExpr>(ExistingInit))
2466 StructuredList = E->getUpdater();
2467 else {
2468 DesignatedInitUpdateExpr *DIUE = new (SemaRef.Context)
2469 DesignatedInitUpdateExpr(SemaRef.Context, D->getBeginLoc(),
2470 ExistingInit, DIE->getEndLoc());
2471 StructuredList->updateInit(SemaRef.Context, StructuredIndex, DIUE);
2472 StructuredList = DIUE->getUpdater();
2473 }
2474 } else {
2475 // We don't need to track the structured representation of a
2476 // designated init update of an already-fully-initialized object in
2477 // verify-only mode. The only reason we would need the structure is
2478 // to determine where the uninitialized "holes" are, and in this
2479 // case, we know there aren't any and we can't introduce any.
2480 StructuredList = nullptr;
2481 }
2482 }
2483 }
2484 }
2485
2486 if (D->isFieldDesignator()) {
2487 // C99 6.7.8p7:
2488 //
2489 // If a designator has the form
2490 //
2491 // . identifier
2492 //
2493 // then the current object (defined below) shall have
2494 // structure or union type and the identifier shall be the
2495 // name of a member of that type.
2496 const RecordType *RT = CurrentObjectType->getAs<RecordType>();
2497 if (!RT) {
2498 SourceLocation Loc = D->getDotLoc();
2499 if (Loc.isInvalid())
2500 Loc = D->getFieldLoc();
2501 if (!VerifyOnly)
2502 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
2503 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
2504 ++Index;
2505 return true;
2506 }
2507
2508 FieldDecl *KnownField = D->getField();
2509 if (!KnownField) {
2510 IdentifierInfo *FieldName = D->getFieldName();
2511 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
2512 for (NamedDecl *ND : Lookup) {
2513 if (auto *FD = dyn_cast<FieldDecl>(ND)) {
2514 KnownField = FD;
2515 break;
2516 }
2517 if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
2518 // In verify mode, don't modify the original.
2519 if (VerifyOnly)
2520 DIE = CloneDesignatedInitExpr(SemaRef, DIE);
2521 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
2522 D = DIE->getDesignator(DesigIdx);
2523 KnownField = cast<FieldDecl>(*IFD->chain_begin());
2524 break;
2525 }
2526 }
2527 if (!KnownField) {
2528 if (VerifyOnly) {
2529 ++Index;
2530 return true; // No typo correction when just trying this out.
2531 }
2532
2533 // Name lookup found something, but it wasn't a field.
2534 if (!Lookup.empty()) {
2535 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
2536 << FieldName;
2537 SemaRef.Diag(Lookup.front()->getLocation(),
2538 diag::note_field_designator_found);
2539 ++Index;
2540 return true;
2541 }
2542
2543 // Name lookup didn't find anything.
2544 // Determine whether this was a typo for another field name.
2545 FieldInitializerValidatorCCC CCC(RT->getDecl());
2546 if (TypoCorrection Corrected = SemaRef.CorrectTypo(
2547 DeclarationNameInfo(FieldName, D->getFieldLoc()),
2548 Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr, CCC,
2549 Sema::CTK_ErrorRecovery, RT->getDecl())) {
2550 SemaRef.diagnoseTypo(
2551 Corrected,
2552 SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
2553 << FieldName << CurrentObjectType);
2554 KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
2555 hadError = true;
2556 } else {
2557 // Typo correction didn't find anything.
2558 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
2559 << FieldName << CurrentObjectType;
2560 ++Index;
2561 return true;
2562 }
2563 }
2564 }
2565
2566 unsigned NumBases = 0;
2567 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2568 NumBases = CXXRD->getNumBases();
2569
2570 unsigned FieldIndex = NumBases;
2571
2572 for (auto *FI : RT->getDecl()->fields()) {
2573 if (FI->isUnnamedBitfield())
2574 continue;
2575 if (declaresSameEntity(KnownField, FI)) {
2576 KnownField = FI;
2577 break;
2578 }
2579 ++FieldIndex;
2580 }
2581
2582 RecordDecl::field_iterator Field =
2583 RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));
2584
2585 // All of the fields of a union are located at the same place in
2586 // the initializer list.
2587 if (RT->getDecl()->isUnion()) {
2588 FieldIndex = 0;
2589 if (StructuredList) {
2590 FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
2591 if (CurrentField && !declaresSameEntity(CurrentField, *Field)) {
2592 assert(StructuredList->getNumInits() == 1
2593 && "A union should never have more than one initializer!");
2594
2595 Expr *ExistingInit = StructuredList->getInit(0);
2596 if (ExistingInit) {
2597 // We're about to throw away an initializer, emit warning.
2598 diagnoseInitOverride(
2599 ExistingInit, SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2600 }
2601
2602 // remove existing initializer
2603 StructuredList->resizeInits(SemaRef.Context, 0);
2604 StructuredList->setInitializedFieldInUnion(nullptr);
2605 }
2606
2607 StructuredList->setInitializedFieldInUnion(*Field);
2608 }
2609 }
2610
2611 // Make sure we can use this declaration.
2612 bool InvalidUse;
2613 if (VerifyOnly)
2614 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2615 else
2616 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
2617 if (InvalidUse) {
2618 ++Index;
2619 return true;
2620 }
2621
2622 // C++20 [dcl.init.list]p3:
2623 // The ordered identifiers in the designators of the designated-
2624 // initializer-list shall form a subsequence of the ordered identifiers
2625 // in the direct non-static data members of T.
2626 //
2627 // Note that this is not a condition on forming the aggregate
2628 // initialization, only on actually performing initialization,
2629 // so it is not checked in VerifyOnly mode.
2630 //
2631 // FIXME: This is the only reordering diagnostic we produce, and it only
2632 // catches cases where we have a top-level field designator that jumps
2633 // backwards. This is the only such case that is reachable in an
2634 // otherwise-valid C++20 program, so is the only case that's required for
2635 // conformance, but for consistency, we should diagnose all the other
2636 // cases where a designator takes us backwards too.
2637 if (IsFirstDesignator && !VerifyOnly && SemaRef.getLangOpts().CPlusPlus &&
2638 NextField &&
2639 (*NextField == RT->getDecl()->field_end() ||
2640 (*NextField)->getFieldIndex() > Field->getFieldIndex() + 1)) {
2641 // Find the field that we just initialized.
2642 FieldDecl *PrevField = nullptr;
2643 for (auto FI = RT->getDecl()->field_begin();
2644 FI != RT->getDecl()->field_end(); ++FI) {
2645 if (FI->isUnnamedBitfield())
2646 continue;
2647 if (*NextField != RT->getDecl()->field_end() &&
2648 declaresSameEntity(*FI, **NextField))
2649 break;
2650 PrevField = *FI;
2651 }
2652
2653 if (PrevField &&
2654 PrevField->getFieldIndex() > KnownField->getFieldIndex()) {
2655 SemaRef.Diag(DIE->getBeginLoc(), diag::ext_designated_init_reordered)
2656 << KnownField << PrevField << DIE->getSourceRange();
2657
2658 unsigned OldIndex = NumBases + PrevField->getFieldIndex();
2659 if (StructuredList && OldIndex <= StructuredList->getNumInits()) {
2660 if (Expr *PrevInit = StructuredList->getInit(OldIndex)) {
2661 SemaRef.Diag(PrevInit->getBeginLoc(),
2662 diag::note_previous_field_init)
2663 << PrevField << PrevInit->getSourceRange();
2664 }
2665 }
2666 }
2667 }
2668
2669
2670 // Update the designator with the field declaration.
2671 if (!VerifyOnly)
2672 D->setField(*Field);
2673
2674 // Make sure that our non-designated initializer list has space
2675 // for a subobject corresponding to this field.
2676 if (StructuredList && FieldIndex >= StructuredList->getNumInits())
2677 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
2678
2679 // This designator names a flexible array member.
2680 if (Field->getType()->isIncompleteArrayType()) {
2681 bool Invalid = false;
2682 if ((DesigIdx + 1) != DIE->size()) {
2683 // We can't designate an object within the flexible array
2684 // member (because GCC doesn't allow it).
2685 if (!VerifyOnly) {
2686 DesignatedInitExpr::Designator *NextD
2687 = DIE->getDesignator(DesigIdx + 1);
2688 SemaRef.Diag(NextD->getBeginLoc(),
2689 diag::err_designator_into_flexible_array_member)
2690 << SourceRange(NextD->getBeginLoc(), DIE->getEndLoc());
2691 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2692 << *Field;
2693 }
2694 Invalid = true;
2695 }
2696
2697 if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
2698 !isa<StringLiteral>(DIE->getInit())) {
2699 // The initializer is not an initializer list.
2700 if (!VerifyOnly) {
2701 SemaRef.Diag(DIE->getInit()->getBeginLoc(),
2702 diag::err_flexible_array_init_needs_braces)
2703 << DIE->getInit()->getSourceRange();
2704 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2705 << *Field;
2706 }
2707 Invalid = true;
2708 }
2709
2710 // Check GNU flexible array initializer.
2711 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
2712 TopLevelObject))
2713 Invalid = true;
2714
2715 if (Invalid) {
2716 ++Index;
2717 return true;
2718 }
2719
2720 // Initialize the array.
2721 bool prevHadError = hadError;
2722 unsigned newStructuredIndex = FieldIndex;
2723 unsigned OldIndex = Index;
2724 IList->setInit(Index, DIE->getInit());
2725
2726 InitializedEntity MemberEntity =
2727 InitializedEntity::InitializeMember(*Field, &Entity);
2728 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2729 StructuredList, newStructuredIndex);
2730
2731 IList->setInit(OldIndex, DIE);
2732 if (hadError && !prevHadError) {
2733 ++Field;
2734 ++FieldIndex;
2735 if (NextField)
2736 *NextField = Field;
2737 StructuredIndex = FieldIndex;
2738 return true;
2739 }
2740 } else {
2741 // Recurse to check later designated subobjects.
2742 QualType FieldType = Field->getType();
2743 unsigned newStructuredIndex = FieldIndex;
2744
2745 InitializedEntity MemberEntity =
2746 InitializedEntity::InitializeMember(*Field, &Entity);
2747 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
2748 FieldType, nullptr, nullptr, Index,
2749 StructuredList, newStructuredIndex,
2750 FinishSubobjectInit, false))
2751 return true;
2752 }
2753
2754 // Find the position of the next field to be initialized in this
2755 // subobject.
2756 ++Field;
2757 ++FieldIndex;
2758
2759 // If this the first designator, our caller will continue checking
2760 // the rest of this struct/class/union subobject.
2761 if (IsFirstDesignator) {
2762 if (NextField)
2763 *NextField = Field;
2764 StructuredIndex = FieldIndex;
2765 return false;
2766 }
2767
2768 if (!FinishSubobjectInit)
2769 return false;
2770
2771 // We've already initialized something in the union; we're done.
2772 if (RT->getDecl()->isUnion())
2773 return hadError;
2774
2775 // Check the remaining fields within this class/struct/union subobject.
2776 bool prevHadError = hadError;
2777
2778 auto NoBases =
2779 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
2780 CXXRecordDecl::base_class_iterator());
2781 CheckStructUnionTypes(Entity, IList, CurrentObjectType, NoBases, Field,
2782 false, Index, StructuredList, FieldIndex);
2783 return hadError && !prevHadError;
2784 }
2785
2786 // C99 6.7.8p6:
2787 //
2788 // If a designator has the form
2789 //
2790 // [ constant-expression ]
2791 //
2792 // then the current object (defined below) shall have array
2793 // type and the expression shall be an integer constant
2794 // expression. If the array is of unknown size, any
2795 // nonnegative value is valid.
2796 //
2797 // Additionally, cope with the GNU extension that permits
2798 // designators of the form
2799 //
2800 // [ constant-expression ... constant-expression ]
2801 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
2802 if (!AT) {
2803 if (!VerifyOnly)
2804 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
2805 << CurrentObjectType;
2806 ++Index;
2807 return true;
2808 }
2809
2810 Expr *IndexExpr = nullptr;
2811 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
2812 if (D->isArrayDesignator()) {
2813 IndexExpr = DIE->getArrayIndex(*D);
2814 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
2815 DesignatedEndIndex = DesignatedStartIndex;
2816 } else {
2817 assert(D->isArrayRangeDesignator() && "Need array-range designator");
2818
2819 DesignatedStartIndex =
2820 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
2821 DesignatedEndIndex =
2822 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
2823 IndexExpr = DIE->getArrayRangeEnd(*D);
2824
2825 // Codegen can't handle evaluating array range designators that have side
2826 // effects, because we replicate the AST value for each initialized element.
2827 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
2828 // elements with something that has a side effect, so codegen can emit an
2829 // "error unsupported" error instead of miscompiling the app.
2830 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
2831 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
2832 FullyStructuredList->sawArrayRangeDesignator();
2833 }
2834
2835 if (isa<ConstantArrayType>(AT)) {
2836 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
2837 DesignatedStartIndex
2838 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
2839 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
2840 DesignatedEndIndex
2841 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
2842 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
2843 if (DesignatedEndIndex >= MaxElements) {
2844 if (!VerifyOnly)
2845 SemaRef.Diag(IndexExpr->getBeginLoc(),
2846 diag::err_array_designator_too_large)
2847 << DesignatedEndIndex.toString(10) << MaxElements.toString(10)
2848 << IndexExpr->getSourceRange();
2849 ++Index;
2850 return true;
2851 }
2852 } else {
2853 unsigned DesignatedIndexBitWidth =
2854 ConstantArrayType::getMaxSizeBits(SemaRef.Context);
2855 DesignatedStartIndex =
2856 DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
2857 DesignatedEndIndex =
2858 DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
2859 DesignatedStartIndex.setIsUnsigned(true);
2860 DesignatedEndIndex.setIsUnsigned(true);
2861 }
2862
2863 bool IsStringLiteralInitUpdate =
2864 StructuredList && StructuredList->isStringLiteralInit();
2865 if (IsStringLiteralInitUpdate && VerifyOnly) {
2866 // We're just verifying an update to a string literal init. We don't need
2867 // to split the string up into individual characters to do that.
2868 StructuredList = nullptr;
2869 } else if (IsStringLiteralInitUpdate) {
2870 // We're modifying a string literal init; we have to decompose the string
2871 // so we can modify the individual characters.
2872 ASTContext &Context = SemaRef.Context;
2873 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens();
2874
2875 // Compute the character type
2876 QualType CharTy = AT->getElementType();
2877
2878 // Compute the type of the integer literals.
2879 QualType PromotedCharTy = CharTy;
2880 if (CharTy->isPromotableIntegerType())
2881 PromotedCharTy = Context.getPromotedIntegerType(CharTy);
2882 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);
2883
2884 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
2885 // Get the length of the string.
2886 uint64_t StrLen = SL->getLength();
2887 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2888 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2889 StructuredList->resizeInits(Context, StrLen);
2890
2891 // Build a literal for each character in the string, and put them into
2892 // the init list.
2893 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2894 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
2895 Expr *Init = new (Context) IntegerLiteral(
2896 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2897 if (CharTy != PromotedCharTy)
2898 Init =
2899 ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, Init,
2900 nullptr, VK_RValue, FPOptionsOverride());
2901 StructuredList->updateInit(Context, i, Init);
2902 }
2903 } else {
2904 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
2905 std::string Str;
2906 Context.getObjCEncodingForType(E->getEncodedType(), Str);
2907
2908 // Get the length of the string.
2909 uint64_t StrLen = Str.size();
2910 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2911 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2912 StructuredList->resizeInits(Context, StrLen);
2913
2914 // Build a literal for each character in the string, and put them into
2915 // the init list.
2916 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2917 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
2918 Expr *Init = new (Context) IntegerLiteral(
2919 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2920 if (CharTy != PromotedCharTy)
2921 Init =
2922 ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, Init,
2923 nullptr, VK_RValue, FPOptionsOverride());
2924 StructuredList->updateInit(Context, i, Init);
2925 }
2926 }
2927 }
2928
2929 // Make sure that our non-designated initializer list has space
2930 // for a subobject corresponding to this array element.
2931 if (StructuredList &&
2932 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
2933 StructuredList->resizeInits(SemaRef.Context,
2934 DesignatedEndIndex.getZExtValue() + 1);
2935
2936 // Repeatedly perform subobject initializations in the range
2937 // [DesignatedStartIndex, DesignatedEndIndex].
2938
2939 // Move to the next designator
2940 unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
2941 unsigned OldIndex = Index;
2942
2943 InitializedEntity ElementEntity =
2944 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
2945
2946 while (DesignatedStartIndex <= DesignatedEndIndex) {
2947 // Recurse to check later designated subobjects.
2948 QualType ElementType = AT->getElementType();
2949 Index = OldIndex;
2950
2951 ElementEntity.setElementIndex(ElementIndex);
2952 if (CheckDesignatedInitializer(
2953 ElementEntity, IList, DIE, DesigIdx + 1, ElementType, nullptr,
2954 nullptr, Index, StructuredList, ElementIndex,
2955 FinishSubobjectInit && (DesignatedStartIndex == DesignatedEndIndex),
2956 false))
2957 return true;
2958
2959 // Move to the next index in the array that we'll be initializing.
2960 ++DesignatedStartIndex;
2961 ElementIndex = DesignatedStartIndex.getZExtValue();
2962 }
2963
2964 // If this the first designator, our caller will continue checking
2965 // the rest of this array subobject.
2966 if (IsFirstDesignator) {
2967 if (NextElementIndex)
2968 *NextElementIndex = DesignatedStartIndex;
2969 StructuredIndex = ElementIndex;
2970 return false;
2971 }
2972
2973 if (!FinishSubobjectInit)
2974 return false;
2975
2976 // Check the remaining elements within this array subobject.
2977 bool prevHadError = hadError;
2978 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
2979 /*SubobjectIsDesignatorContext=*/false, Index,
2980 StructuredList, ElementIndex);
2981 return hadError && !prevHadError;
2982}
2983
2984// Get the structured initializer list for a subobject of type
2985// @p CurrentObjectType.
2986InitListExpr *
2987InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
2988 QualType CurrentObjectType,
2989 InitListExpr *StructuredList,
2990 unsigned StructuredIndex,
2991 SourceRange InitRange,
2992 bool IsFullyOverwritten) {
2993 if (!StructuredList)
2994 return nullptr;
2995
2996 Expr *ExistingInit = nullptr;
2997 if (StructuredIndex < StructuredList->getNumInits())
2998 ExistingInit = StructuredList->getInit(StructuredIndex);
2999
3000 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
3001 // There might have already been initializers for subobjects of the current
3002 // object, but a subsequent initializer list will overwrite the entirety
3003 // of the current object. (See DR 253 and C99 6.7.8p21). e.g.,
3004 //
3005 // struct P { char x[6]; };
3006 // struct P l = { .x[2] = 'x', .x = { [0] = 'f' } };
3007 //
3008 // The first designated initializer is ignored, and l.x is just "f".
3009 if (!IsFullyOverwritten)
3010 return Result;
3011
3012 if (ExistingInit) {
3013 // We are creating an initializer list that initializes the
3014 // subobjects of the current object, but there was already an
3015 // initialization that completely initialized the current
3016 // subobject:
3017 //
3018 // struct X { int a, b; };
3019 // struct X xs[] = { [0] = { 1, 2 }, [0].b = 3 };
3020 //
3021 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
3022 // designated initializer overwrites the [0].b initializer
3023 // from the prior initialization.
3024 //
3025 // When the existing initializer is an expression rather than an
3026 // initializer list, we cannot decompose and update it in this way.
3027 // For example:
3028 //
3029 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
3030 //
3031 // This case is handled by CheckDesignatedInitializer.
3032 diagnoseInitOverride(ExistingInit, InitRange);
3033 }
3034
3035 unsigned ExpectedNumInits = 0;
3036 if (Index < IList->getNumInits()) {
3037 if (auto *Init = dyn_cast_or_null<InitListExpr>(IList->getInit(Index)))
3038 ExpectedNumInits = Init->getNumInits();
3039 else
3040 ExpectedNumInits = IList->getNumInits() - Index;
3041 }
3042
3043 InitListExpr *Result =
3044 createInitListExpr(CurrentObjectType, InitRange, ExpectedNumInits);
3045
3046 // Link this new initializer list into the structured initializer
3047 // lists.
3048 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
3049 return Result;
3050}
3051
3052InitListExpr *
3053InitListChecker::createInitListExpr(QualType CurrentObjectType,
3054 SourceRange InitRange,
3055 unsigned ExpectedNumInits) {
3056 InitListExpr *Result
3057 = new (SemaRef.Context) InitListExpr(SemaRef.Context,
3058 InitRange.getBegin(), None,
3059 InitRange.getEnd());
3060
3061 QualType ResultType = CurrentObjectType;
3062 if (!ResultType->isArrayType())
3063 ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
3064 Result->setType(ResultType);
3065
3066 // Pre-allocate storage for the structured initializer list.
3067 unsigned NumElements = 0;
3068
3069 if (const ArrayType *AType
3070 = SemaRef.Context.getAsArrayType(CurrentObjectType)) {
3071 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
3072 NumElements = CAType->getSize().getZExtValue();
3073 // Simple heuristic so that we don't allocate a very large
3074 // initializer with many empty entries at the end.
3075 if (NumElements > ExpectedNumInits)
3076 NumElements = 0;
3077 }
3078 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) {
3079 NumElements = VType->getNumElements();
3080 } else if (CurrentObjectType->isRecordType()) {
3081 NumElements = numStructUnionElements(CurrentObjectType);
3082 }
3083
3084 Result->reserveInits(SemaRef.Context, NumElements);
3085
3086 return Result;
3087}
3088
3089/// Update the initializer at index @p StructuredIndex within the
3090/// structured initializer list to the value @p expr.
3091void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
3092 unsigned &StructuredIndex,
3093 Expr *expr) {
3094 // No structured initializer list to update
3095 if (!StructuredList)
3096 return;
3097
3098 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
3099 StructuredIndex, expr)) {
3100 // This initializer overwrites a previous initializer.
3101 // No need to diagnose when `expr` is nullptr because a more relevant
3102 // diagnostic has already been issued and this diagnostic is potentially
3103 // noise.
3104 if (expr)
3105 diagnoseInitOverride(PrevInit, expr->getSourceRange());
3106 }
3107
3108 ++StructuredIndex;
3109}
3110
3111/// Determine whether we can perform aggregate initialization for the purposes
3112/// of overload resolution.
3113bool Sema::CanPerformAggregateInitializationForOverloadResolution(
3114 const InitializedEntity &Entity, InitListExpr *From) {
3115 QualType Type = Entity.getType();
3116 InitListChecker Check(*this, Entity, From, Type, /*VerifyOnly=*/true,
3117 /*TreatUnavailableAsInvalid=*/false,
3118 /*InOverloadResolution=*/true);
3119 return !Check.HadError();
3120}
3121
3122/// Check that the given Index expression is a valid array designator
3123/// value. This is essentially just a wrapper around
3124/// VerifyIntegerConstantExpression that also checks for negative values
3125/// and produces a reasonable diagnostic if there is a
3126/// failure. Returns the index expression, possibly with an implicit cast
3127/// added, on success. If everything went okay, Value will receive the
3128/// value of the constant expression.
3129static ExprResult
3130CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
3131 SourceLocation Loc = Index->getBeginLoc();
3132
3133 // Make sure this is an integer constant expression.
3134 ExprResult Result =
3135 S.VerifyIntegerConstantExpression(Index, &Value, Sema::AllowFold);
3136 if (Result.isInvalid())
3137 return Result;
3138
3139 if (Value.isSigned() && Value.isNegative())
3140 return S.Diag(Loc, diag::err_array_designator_negative)
3141 << Value.toString(10) << Index->getSourceRange();
3142
3143 Value.setIsUnsigned(true);
3144 return Result;
3145}
3146
3147ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
3148 SourceLocation EqualOrColonLoc,
3149 bool GNUSyntax,
3150 ExprResult Init) {
3151 typedef DesignatedInitExpr::Designator ASTDesignator;
3152
3153 bool Invalid = false;
3154 SmallVector<ASTDesignator, 32> Designators;
3155 SmallVector<Expr *, 32> InitExpressions;
3156
3157 // Build designators and check array designator expressions.
3158 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
3159 const Designator &D = Desig.getDesignator(Idx);
3160 switch (D.getKind()) {
3161 case Designator::FieldDesignator:
3162 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
3163 D.getFieldLoc()));
3164 break;
3165
3166 case Designator::ArrayDesignator: {
3167 Expr *Index = static_cast<Expr *>(D.getArrayIndex());
3168 llvm::APSInt IndexValue;
3169 if (!Index->isTypeDependent() && !Index->isValueDependent())
3170 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
3171 if (!Index)
3172 Invalid = true;
3173 else {
3174 Designators.push_back(ASTDesignator(InitExpressions.size(),
3175 D.getLBracketLoc(),
3176 D.getRBracketLoc()));
3177 InitExpressions.push_back(Index);
3178 }
3179 break;
3180 }
3181
3182 case Designator::ArrayRangeDesignator: {
3183 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
3184 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
3185 llvm::APSInt StartValue;
3186 llvm::APSInt EndValue;
3187 bool StartDependent = StartIndex->isTypeDependent() ||
3188 StartIndex->isValueDependent();
3189 bool EndDependent = EndIndex->isTypeDependent() ||
3190 EndIndex->isValueDependent();
3191 if (!StartDependent)
3192 StartIndex =
3193 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
3194 if (!EndDependent)
3195 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();
3196
3197 if (!StartIndex || !EndIndex)
3198 Invalid = true;
3199 else {
3200 // Make sure we're comparing values with the same bit width.
3201 if (StartDependent || EndDependent) {
3202 // Nothing to compute.
3203 } else if (StartValue.getBitWidth() > EndValue.getBitWidth())
3204 EndValue = EndValue.extend(StartValue.getBitWidth());
3205 else if (StartValue.getBitWidth() < EndValue.getBitWidth())
3206 StartValue = StartValue.extend(EndValue.getBitWidth());
3207
3208 if (!StartDependent && !EndDependent && EndValue < StartValue) {
3209 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
3210 << StartValue.toString(10) << EndValue.toString(10)
3211 << StartIndex->getSourceRange() << EndIndex->getSourceRange();
3212 Invalid = true;
3213 } else {
3214 Designators.push_back(ASTDesignator(InitExpressions.size(),
3215 D.getLBracketLoc(),
3216 D.getEllipsisLoc(),
3217 D.getRBracketLoc()));
3218 InitExpressions.push_back(StartIndex);
3219 InitExpressions.push_back(EndIndex);
3220 }
3221 }
3222 break;
3223 }
3224 }
3225 }
3226
3227 if (Invalid || Init.isInvalid())
3228 return ExprError();
3229
3230 // Clear out the expressions within the designation.
3231 Desig.ClearExprs(*this);
3232
3233 return DesignatedInitExpr::Create(Context, Designators, InitExpressions,
3234 EqualOrColonLoc, GNUSyntax,
3235 Init.getAs<Expr>());
3236}
3237
3238//===----------------------------------------------------------------------===//
3239// Initialization entity
3240//===----------------------------------------------------------------------===//
3241
3242InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
3243 const InitializedEntity &Parent)
3244 : Parent(&Parent), Index(Index)
3245{
3246 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
3247 Kind = EK_ArrayElement;
3248 Type = AT->getElementType();
3249 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
3250 Kind = EK_VectorElement;
3251 Type = VT->getElementType();
3252 } else {
3253 const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
3254 assert(CT && "Unexpected type");
3255 Kind = EK_ComplexElement;
3256 Type = CT->getElementType();
3257 }
3258}
3259
3260InitializedEntity
3261InitializedEntity::InitializeBase(ASTContext &Context,
3262 const CXXBaseSpecifier *Base,
3263 bool IsInheritedVirtualBase,
3264 const InitializedEntity *Parent) {
3265 InitializedEntity Result;
3266 Result.Kind = EK_Base;
3267 Result.Parent = Parent;
3268 Result.Base = reinterpret_cast<uintptr_t>(Base);
3269 if (IsInheritedVirtualBase)
3270 Result.Base |= 0x01;
3271
3272 Result.Type = Base->getType();
3273 return Result;
3274}
3275
3276DeclarationName InitializedEntity::getName() const {
3277 switch (getKind()) {
3278 case EK_Parameter:
3279 case EK_Parameter_CF_Audited: {
3280 ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
3281 return (D ? D->getDeclName() : DeclarationName());
3282 }
3283
3284 case EK_Variable:
3285 case EK_Member:
3286 case EK_Binding:
3287 case EK_TemplateParameter:
3288 return Variable.VariableOrMember->getDeclName();
3289
3290 case EK_LambdaCapture:
3291 return DeclarationName(Capture.VarID);
3292
3293 case EK_Result:
3294 case EK_StmtExprResult:
3295 case EK_Exception:
3296 case EK_New:
3297 case EK_Temporary:
3298 case EK_Base:
3299 case EK_Delegating:
3300 case EK_ArrayElement:
3301 case EK_VectorElement:
3302 case EK_ComplexElement:
3303 case EK_BlockElement:
3304 case EK_LambdaToBlockConversionBlockElement:
3305 case EK_CompoundLiteralInit:
3306 case EK_RelatedResult:
3307 return DeclarationName();
3308 }
3309
3310 llvm_unreachable("Invalid EntityKind!");
3311}
3312
3313ValueDecl *InitializedEntity::getDecl() const {
3314 switch (getKind()) {
3315 case EK_Variable:
3316 case EK_Member:
3317 case EK_Binding:
3318 case EK_TemplateParameter:
3319 return Variable.VariableOrMember;
3320
3321 case EK_Parameter:
3322 case EK_Parameter_CF_Audited:
3323 return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
3324
3325 case EK_Result:
3326 case EK_StmtExprResult:
3327 case EK_Exception:
3328 case EK_New:
3329 case EK_Temporary:
3330 case EK_Base:
3331 case EK_Delegating:
3332 case EK_ArrayElement:
3333 case EK_VectorElement:
3334 case EK_ComplexElement:
3335 case EK_BlockElement:
3336 case EK_LambdaToBlockConversionBlockElement:
3337 case EK_LambdaCapture:
3338 case EK_CompoundLiteralInit:
3339 case EK_RelatedResult:
3340 return nullptr;
3341 }
3342
3343 llvm_unreachable("Invalid EntityKind!");
3344}
3345
3346bool InitializedEntity::allowsNRVO() const {
3347 switch (getKind()) {
3348 case EK_Result:
3349 case EK_Exception:
3350 return LocAndNRVO.NRVO;
3351
3352 case EK_StmtExprResult:
3353 case EK_Variable:
3354 case EK_Parameter:
3355 case EK_Parameter_CF_Audited:
3356 case EK_TemplateParameter:
3357 case EK_Member:
3358 case EK_Binding:
3359 case EK_New:
3360 case EK_Temporary:
3361 case EK_CompoundLiteralInit:
3362 case EK_Base:
3363 case EK_Delegating:
3364 case EK_ArrayElement:
3365 case EK_VectorElement:
3366 case EK_ComplexElement:
3367 case EK_BlockElement:
3368 case EK_LambdaToBlockConversionBlockElement:
3369 case EK_LambdaCapture:
3370 case EK_RelatedResult:
3371 break;
3372 }
3373
3374 return false;
3375}
3376
3377unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
3378 assert(getParent() != this);
3379 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
3380 for (unsigned I = 0; I != Depth; ++I)
3381 OS << "`-";
3382
3383 switch (getKind()) {
3384 case EK_Variable: OS << "Variable"; break;
3385 case EK_Parameter: OS << "Parameter"; break;
3386 case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
3387 break;
3388 case EK_TemplateParameter: OS << "TemplateParameter"; break;
3389 case EK_Result: OS << "Result"; break;
3390 case EK_StmtExprResult: OS << "StmtExprResult"; break;
3391 case EK_Exception: OS << "Exception"; break;
3392 case EK_Member: OS << "Member"; break;
3393 case EK_Binding: OS << "Binding"; break;
3394 case EK_New: OS << "New"; break;
3395 case EK_Temporary: OS << "Temporary"; break;
3396 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
3397 case EK_RelatedResult: OS << "RelatedResult"; break;
3398 case EK_Base: OS << "Base"; break;
3399 case EK_Delegating: OS << "Delegating"; break;
3400 case EK_ArrayElement: OS << "ArrayElement " << Index; break;
3401 case EK_VectorElement: OS << "VectorElement " << Index; break;
3402 case EK_ComplexElement: OS << "ComplexElement " << Index; break;
3403 case EK_BlockElement: OS << "Block"; break;
3404 case EK_LambdaToBlockConversionBlockElement:
3405 OS << "Block (lambda)";
3406 break;
3407 case EK_LambdaCapture:
3408 OS << "LambdaCapture ";
3409 OS << DeclarationName(Capture.VarID);
3410 break;
3411 }
3412
3413 if (auto *D = getDecl()) {
3414 OS << " ";
3415 D->printQualifiedName(OS);
3416 }
3417
3418 OS << " '" << getType().getAsString() << "'\n";
3419
3420 return Depth + 1;
3421}
3422
3423LLVM_DUMP_METHOD void InitializedEntity::dump() const {
3424 dumpImpl(llvm::errs());
3425}
3426
3427//===----------------------------------------------------------------------===//
3428// Initialization sequence
3429//===----------------------------------------------------------------------===//
3430
3431void InitializationSequence::Step::Destroy() {
3432 switch (Kind) {
3433 case SK_ResolveAddressOfOverloadedFunction:
3434 case SK_CastDerivedToBaseRValue:
3435 case SK_CastDerivedToBaseXValue:
3436 case SK_CastDerivedToBaseLValue:
3437 case SK_BindReference:
3438 case SK_BindReferenceToTemporary:
3439 case SK_FinalCopy:
3440 case SK_ExtraneousCopyToTemporary:
3441 case SK_UserConversion:
3442 case SK_QualificationConversionRValue:
3443 case SK_QualificationConversionXValue:
3444 case SK_QualificationConversionLValue:
3445 case SK_FunctionReferenceConversion:
3446 case SK_AtomicConversion:
3447 case SK_ListInitialization:
3448 case SK_UnwrapInitList:
3449 case SK_RewrapInitList:
3450 case SK_ConstructorInitialization:
3451 case SK_ConstructorInitializationFromList:
3452 case SK_ZeroInitialization:
3453 case SK_CAssignment:
3454 case SK_StringInit:
3455 case SK_ObjCObjectConversion:
3456 case SK_ArrayLoopIndex:
3457 case SK_ArrayLoopInit:
3458 case SK_ArrayInit:
3459 case SK_GNUArrayInit:
3460 case SK_ParenthesizedArrayInit:
3461 case SK_PassByIndirectCopyRestore:
3462 case SK_PassByIndirectRestore:
3463 case SK_ProduceObjCObject:
3464 case SK_StdInitializerList:
3465 case SK_StdInitializerListConstructorCall:
3466 case SK_OCLSamplerInit:
3467 case SK_OCLZeroOpaqueType:
3468 break;
3469
3470 case SK_ConversionSequence:
3471 case SK_ConversionSequenceNoNarrowing:
3472 delete ICS;
3473 }
3474}
3475
3476bool InitializationSequence::isDirectReferenceBinding() const {
3477 // There can be some lvalue adjustments after the SK_BindReference step.
3478 for (auto I = Steps.rbegin(); I != Steps.rend(); ++I) {
3479 if (I->Kind == SK_BindReference)
3480 return true;
3481 if (I->Kind == SK_BindReferenceToTemporary)
3482 return false;
3483 }
3484 return false;
3485}
3486
3487bool InitializationSequence::isAmbiguous() const {
3488 if (!Failed())
3489 return false;
3490
3491 switch (getFailureKind()) {
3492 case FK_TooManyInitsForReference:
3493 case FK_ParenthesizedListInitForReference:
3494 case FK_ArrayNeedsInitList:
3495 case FK_ArrayNeedsInitListOrStringLiteral:
3496 case FK_ArrayNeedsInitListOrWideStringLiteral:
3497 case FK_NarrowStringIntoWideCharArray:
3498 case FK_WideStringIntoCharArray:
3499 case FK_IncompatWideStringIntoWideChar:
3500 case FK_PlainStringIntoUTF8Char:
3501 case FK_UTF8StringIntoPlainChar:
3502 case FK_AddressOfOverloadFailed: // FIXME: Could do better
3503 case FK_NonConstLValueReferenceBindingToTemporary:
3504 case FK_NonConstLValueReferenceBindingToBitfield:
3505 case FK_NonConstLValueReferenceBindingToVectorElement:
3506 case FK_NonConstLValueReferenceBindingToMatrixElement:
3507 case FK_NonConstLValueReferenceBindingToUnrelated:
3508 case FK_RValueReferenceBindingToLValue:
3509 case FK_ReferenceAddrspaceMismatchTemporary:
3510 case FK_ReferenceInitDropsQualifiers:
3511 case FK_ReferenceInitFailed:
3512 case FK_ConversionFailed:
3513 case FK_ConversionFromPropertyFailed:
3514 case FK_TooManyInitsForScalar:
3515 case FK_ParenthesizedListInitForScalar:
3516 case FK_ReferenceBindingToInitList:
3517 case FK_InitListBadDestinationType:
3518 case FK_DefaultInitOfConst:
3519 case FK_Incomplete:
3520 case FK_ArrayTypeMismatch:
3521 case FK_NonConstantArrayInit:
3522 case FK_ListInitializationFailed:
3523 case FK_VariableLengthArrayHasInitializer:
3524 case FK_PlaceholderType:
3525 case FK_ExplicitConstructor:
3526 case FK_AddressOfUnaddressableFunction:
3527 return false;
3528
3529 case FK_ReferenceInitOverloadFailed:
3530 case FK_UserConversionOverloadFailed:
3531 case FK_ConstructorOverloadFailed:
3532 case FK_ListConstructorOverloadFailed:
3533 return FailedOverloadResult == OR_Ambiguous;
3534 }
3535
3536 llvm_unreachable("Invalid EntityKind!");
3537}
3538
3539bool InitializationSequence::isConstructorInitialization() const {
3540 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3541}
3542
3543void
3544InitializationSequence
3545::AddAddressOverloadResolutionStep(FunctionDecl *Function,
3546 DeclAccessPair Found,
3547 bool HadMultipleCandidates) {
3548 Step S;
3549 S.Kind = SK_ResolveAddressOfOverloadedFunction;
3550 S.Type = Function->getType();
3551 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3552 S.Function.Function = Function;
3553 S.Function.FoundDecl = Found;
3554 Steps.push_back(S);
3555}
3556
3557void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
3558 ExprValueKind VK) {
3559 Step S;
3560 switch (VK) {
3561 case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break;
3562 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
3563 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
3564 }
3565 S.Type = BaseType;
3566 Steps.push_back(S);
3567}
3568
3569void InitializationSequence::AddReferenceBindingStep(QualType T,
3570 bool BindingTemporary) {
3571 Step S;
3572 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
3573 S.Type = T;
3574 Steps.push_back(S);
3575}
3576
3577void InitializationSequence::AddFinalCopy(QualType T) {
3578 Step S;
3579 S.Kind = SK_FinalCopy;
3580 S.Type = T;
3581 Steps.push_back(S);
3582}
3583
3584void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
3585 Step S;
3586 S.Kind = SK_ExtraneousCopyToTemporary;
3587 S.Type = T;
3588 Steps.push_back(S);
3589}
3590
3591void
3592InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
3593 DeclAccessPair FoundDecl,
3594 QualType T,
3595 bool HadMultipleCandidates) {
3596 Step S;
3597 S.Kind = SK_UserConversion;
3598 S.Type = T;
3599 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3600 S.Function.Function = Function;
3601 S.Function.FoundDecl = FoundDecl;
3602 Steps.push_back(S);
3603}
3604
3605void InitializationSequence::AddQualificationConversionStep(QualType Ty,
3606 ExprValueKind VK) {
3607 Step S;
3608 S.Kind = SK_QualificationConversionRValue; // work around a gcc warning
3609 switch (VK) {
3610 case VK_RValue:
3611 S.Kind = SK_QualificationConversionRValue;
3612 break;
3613 case VK_XValue:
3614 S.Kind = SK_QualificationConversionXValue;
3615 break;
3616 case VK_LValue:
3617 S.Kind = SK_QualificationConversionLValue;
3618 break;
3619 }
3620 S.Type = Ty;
3621 Steps.push_back(S);
3622}
3623
3624void InitializationSequence::AddFunctionReferenceConversionStep(QualType Ty) {
3625 Step S;
3626 S.Kind = SK_FunctionReferenceConversion;
3627 S.Type = Ty;
3628 Steps.push_back(S);
3629}
3630
3631void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
3632 Step S;
3633 S.Kind = SK_AtomicConversion;
3634 S.Type = Ty;
3635 Steps.push_back(S);
3636}
3637
3638void InitializationSequence::AddConversionSequenceStep(
3639 const ImplicitConversionSequence &ICS, QualType T,
3640 bool TopLevelOfInitList) {
3641 Step S;
3642 S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
3643 : SK_ConversionSequence;
3644 S.Type = T;
3645 S.ICS = new ImplicitConversionSequence(ICS);
3646 Steps.push_back(S);
3647}
3648
3649void InitializationSequence::AddListInitializationStep(QualType T) {
3650 Step S;
3651 S.Kind = SK_ListInitialization;
3652 S.Type = T;
3653 Steps.push_back(S);
3654}
3655
3656void InitializationSequence::AddConstructorInitializationStep(
3657 DeclAccessPair FoundDecl, CXXConstructorDecl *Constructor, QualType T,
3658 bool HadMultipleCandidates, bool FromInitList, bool AsInitList) {
3659 Step S;
3660 S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
3661 : SK_ConstructorInitializationFromList
3662 : SK_ConstructorInitialization;
3663 S.Type = T;
3664 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3665 S.Function.Function = Constructor;
3666 S.Function.FoundDecl = FoundDecl;
3667 Steps.push_back(S);
3668}
3669
3670void InitializationSequence::AddZeroInitializationStep(QualType T) {
3671 Step S;
3672 S.Kind = SK_ZeroInitialization;
3673 S.Type = T;
3674 Steps.push_back(S);
3675}
3676
3677void InitializationSequence::AddCAssignmentStep(QualType T) {
3678 Step S;
3679 S.Kind = SK_CAssignment;
3680 S.Type = T;
3681 Steps.push_back(S);
3682}
3683
3684void InitializationSequence::AddStringInitStep(QualType T) {
3685 Step S;
3686 S.Kind = SK_StringInit;
3687 S.Type = T;
3688 Steps.push_back(S);
3689}
3690
3691void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
3692 Step S;
3693 S.Kind = SK_ObjCObjectConversion;
3694 S.Type = T;
3695 Steps.push_back(S);
3696}
3697
3698void InitializationSequence::AddArrayInitStep(QualType T, bool IsGNUExtension) {
3699 Step S;
3700 S.Kind = IsGNUExtension ? SK_GNUArrayInit : SK_ArrayInit;
3701 S.Type = T;
3702 Steps.push_back(S);
3703}
3704
3705void InitializationSequence::AddArrayInitLoopStep(QualType T, QualType EltT) {
3706 Step S;
3707 S.Kind = SK_ArrayLoopIndex;
3708 S.Type = EltT;
3709 Steps.insert(Steps.begin(), S);
3710
3711 S.Kind = SK_ArrayLoopInit;
3712 S.Type = T;
3713 Steps.push_back(S);
3714}
3715
3716void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
3717 Step S;
3718 S.Kind = SK_ParenthesizedArrayInit;
3719 S.Type = T;
3720 Steps.push_back(S);
3721}
3722
3723void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
3724 bool shouldCopy) {
3725 Step s;
3726 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
3727 : SK_PassByIndirectRestore);
3728 s.Type = type;
3729 Steps.push_back(s);
3730}
3731
3732void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
3733 Step S;
3734 S.Kind = SK_ProduceObjCObject;
3735 S.Type = T;
3736 Steps.push_back(S);
3737}
3738
3739void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
3740 Step S;
3741 S.Kind = SK_StdInitializerList;
3742 S.Type = T;
3743 Steps.push_back(S);
3744}
3745
3746void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
3747 Step S;
3748 S.Kind = SK_OCLSamplerInit;
3749 S.Type = T;
3750 Steps.push_back(S);
3751}
3752
3753void InitializationSequence::AddOCLZeroOpaqueTypeStep(QualType T) {
3754 Step S;
3755 S.Kind = SK_OCLZeroOpaqueType;
3756 S.Type = T;
3757 Steps.push_back(S);
3758}
3759
3760void InitializationSequence::RewrapReferenceInitList(QualType T,
3761 InitListExpr *Syntactic) {
3762 assert(Syntactic->getNumInits() == 1 &&
3763 "Can only rewrap trivial init lists.");
3764 Step S;
3765 S.Kind = SK_UnwrapInitList;
3766 S.Type = Syntactic->getInit(0)->getType();
3767 Steps.insert(Steps.begin(), S);
3768
3769 S.Kind = SK_RewrapInitList;
3770 S.Type = T;
3771 S.WrappingSyntacticList = Syntactic;
3772 Steps.push_back(S);
3773}
3774
3775void InitializationSequence::SetOverloadFailure(FailureKind Failure,
3776 OverloadingResult Result) {
3777 setSequenceKind(FailedSequence);
3778 this->Failure = Failure;
3779 this->FailedOverloadResult = Result;
3780}
3781
3782//===----------------------------------------------------------------------===//
3783// Attempt initialization
3784//===----------------------------------------------------------------------===//
3785
3786/// Tries to add a zero initializer. Returns true if that worked.
3787static bool
3788maybeRecoverWithZeroInitialization(Sema &S, InitializationSequence &Sequence,
3789 const InitializedEntity &Entity) {
3790 if (Entity.getKind() != InitializedEntity::EK_Variable)
3791 return false;
3792
3793 VarDecl *VD = cast<VarDecl>(Entity.getDecl());
3794 if (VD->getInit() || VD->getEndLoc().isMacroID())
3795 return false;
3796
3797 QualType VariableTy = VD->getType().getCanonicalType();
3798 SourceLocation Loc = S.getLocForEndOfToken(VD->getEndLoc());
3799 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
3800 if (!Init.empty()) {
3801 Sequence.AddZeroInitializationStep(Entity.getType());
3802 Sequence.SetZeroInitializationFixit(Init, Loc);
3803 return true;
3804 }
3805 return false;
3806}
3807
3808static void MaybeProduceObjCObject(Sema &S,
3809 InitializationSequence &Sequence,
3810 const InitializedEntity &Entity) {
3811 if (!S.getLangOpts().ObjCAutoRefCount) return;
3812
3813 /// When initializing a parameter, produce the value if it's marked
3814 /// __attribute__((ns_consumed)).
3815 if (Entity.isParameterKind()) {
3816 if (!Entity.isParameterConsumed())
3817 return;
3818
3819 assert(Entity.getType()->isObjCRetainableType() &&
3820 "consuming an object of unretainable type?");
3821 Sequence.AddProduceObjCObjectStep(Entity.getType());
3822
3823 /// When initializing a return value, if the return type is a
3824 /// retainable type, then returns need to immediately retain the
3825 /// object. If an autorelease is required, it will be done at the
3826 /// last instant.
3827 } else if (Entity.getKind() == InitializedEntity::EK_Result ||
3828 Entity.getKind() == InitializedEntity::EK_StmtExprResult) {
3829 if (!Entity.getType()->isObjCRetainableType())
3830 return;
3831
3832 Sequence.AddProduceObjCObjectStep(Entity.getType());
3833 }
3834}
3835
3836static void TryListInitialization(Sema &S,
3837 const InitializedEntity &Entity,
3838 const InitializationKind &Kind,
3839 InitListExpr *InitList,
3840 InitializationSequence &Sequence,
3841 bool TreatUnavailableAsInvalid);
3842
3843/// When initializing from init list via constructor, handle
3844/// initialization of an object of type std::initializer_list<T>.
3845///
3846/// \return true if we have handled initialization of an object of type
3847/// std::initializer_list<T>, false otherwise.
3848static bool TryInitializerListConstruction(Sema &S,
3849 InitListExpr *List,
3850 QualType DestType,
3851 InitializationSequence &Sequence,
3852 bool TreatUnavailableAsInvalid) {
3853 QualType E;
3854 if (!S.isStdInitializerList(DestType, &E))
3855 return false;
3856
3857 if (!S.isCompleteType(List->getExprLoc(), E)) {
3858 Sequence.setIncompleteTypeFailure(E);
3859 return true;
3860 }
3861
3862 // Try initializing a temporary array from the init list.
3863 QualType ArrayType = S.Context.getConstantArrayType(
3864 E.withConst(),
3865 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
3866 List->getNumInits()),
3867 nullptr, clang::ArrayType::Normal, 0);
3868 InitializedEntity HiddenArray =
3869 InitializedEntity::InitializeTemporary(ArrayType);
3870 InitializationKind Kind = InitializationKind::CreateDirectList(
3871 List->getExprLoc(), List->getBeginLoc(), List->getEndLoc());
3872 TryListInitialization(S, HiddenArray, Kind, List, Sequence,
3873 TreatUnavailableAsInvalid);
3874 if (Sequence)
3875 Sequence.AddStdInitializerListConstructionStep(DestType);
3876 return true;
3877}
3878
3879/// Determine if the constructor has the signature of a copy or move
3880/// constructor for the type T of the class in which it was found. That is,
3881/// determine if its first parameter is of type T or reference to (possibly
3882/// cv-qualified) T.
3883static bool hasCopyOrMoveCtorParam(ASTContext &Ctx,
3884 const ConstructorInfo &Info) {
3885 if (Info.Constructor->getNumParams() == 0)
3886 return false;
3887
3888 QualType ParmT =
3889 Info.Constructor->getParamDecl(0)->getType().getNonReferenceType();
3890 QualType ClassT =
3891 Ctx.getRecordType(cast<CXXRecordDecl>(Info.FoundDecl->getDeclContext()));
3892
3893 return Ctx.hasSameUnqualifiedType(ParmT, ClassT);
3894}
3895
3896static OverloadingResult
3897ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
3898 MultiExprArg Args,
3899 OverloadCandidateSet &CandidateSet,
3900 QualType DestType,
3901 DeclContext::lookup_result Ctors,
3902 OverloadCandidateSet::iterator &Best,
3903 bool CopyInitializing, bool AllowExplicit,
3904 bool OnlyListConstructors, bool IsListInit,
3905 bool SecondStepOfCopyInit = false) {
3906 CandidateSet.clear(OverloadCandidateSet::CSK_InitByConstructor);
3907 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
3908
3909 for (NamedDecl *D : Ctors) {
3910 auto Info = getConstructorInfo(D);
3911 if (!Info.Constructor || Info.Constructor->isInvalidDecl())
3912 continue;
3913
3914 if (OnlyListConstructors && !S.isInitListConstructor(Info.Constructor))
3915 continue;
3916
3917 // C++11 [over.best.ics]p4:
3918 // ... and the constructor or user-defined conversion function is a
3919 // candidate by
3920 // - 13.3.1.3, when the argument is the temporary in the second step
3921 // of a class copy-initialization, or
3922 // - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases), [not handled here]
3923 // - the second phase of 13.3.1.7 when the initializer list has exactly
3924 // one element that is itself an initializer list, and the target is
3925 // the first parameter of a constructor of class X, and the conversion
3926 // is to X or reference to (possibly cv-qualified X),
3927 // user-defined conversion sequences are not considered.
3928 bool SuppressUserConversions =
3929 SecondStepOfCopyInit ||
3930 (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
3931 hasCopyOrMoveCtorParam(S.Context, Info));
3932
3933 if (Info.ConstructorTmpl)
3934 S.AddTemplateOverloadCandidate(
3935 Info.ConstructorTmpl, Info.FoundDecl,
3936 /*ExplicitArgs*/ nullptr, Args, CandidateSet, SuppressUserConversions,
3937 /*PartialOverloading=*/false, AllowExplicit);
3938 else {
3939 // C++ [over.match.copy]p1:
3940 // - When initializing a temporary to be bound to the first parameter
3941 // of a constructor [for type T] that takes a reference to possibly
3942 // cv-qualified T as its first argument, called with a single
3943 // argument in the context of direct-initialization, explicit
3944 // conversion functions are also considered.
3945 // FIXME: What if a constructor template instantiates to such a signature?
3946 bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
3947 Args.size() == 1 &&
3948 hasCopyOrMoveCtorParam(S.Context, Info);
3949 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, Args,
3950 CandidateSet, SuppressUserConversions,
3951 /*PartialOverloading=*/false, AllowExplicit,
3952 AllowExplicitConv);
3953 }
3954 }
3955
3956 // FIXME: Work around a bug in C++17 guaranteed copy elision.
3957 //
3958 // When initializing an object of class type T by constructor
3959 // ([over.match.ctor]) or by list-initialization ([over.match.list])
3960 // from a single expression of class type U, conversion functions of
3961 // U that convert to the non-reference type cv T are candidates.
3962 // Explicit conversion functions are only candidates during
3963 // direct-initialization.
3964 //
3965 // Note: SecondStepOfCopyInit is only ever true in this case when
3966 // evaluating whether to produce a C++98 compatibility warning.
3967 if (S.getLangOpts().CPlusPlus17 && Args.size() == 1 &&
3968 !SecondStepOfCopyInit) {
3969 Expr *Initializer = Args[0];
3970 auto *SourceRD = Initializer->getType()->getAsCXXRecordDecl();
3971 if (SourceRD && S.isCompleteType(DeclLoc, Initializer->getType())) {
3972 const auto &Conversions = SourceRD->getVisibleConversionFunctions();
3973 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3974 NamedDecl *D = *I;
3975 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
3976 D = D->getUnderlyingDecl();
3977
3978 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
3979 CXXConversionDecl *Conv;
3980 if (ConvTemplate)
3981 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3982 else
3983 Conv = cast<CXXConversionDecl>(D);
3984
3985 if (ConvTemplate)
3986 S.AddTemplateConversionCandidate(
3987 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
3988 CandidateSet, AllowExplicit, AllowExplicit,
3989 /*AllowResultConversion*/ false);
3990 else
3991 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
3992 DestType, CandidateSet, AllowExplicit,
3993 AllowExplicit,
3994 /*AllowResultConversion*/ false);
3995 }
3996 }
3997 }
3998
3999 // Perform overload resolution and return the result.
4000 return CandidateSet.BestViableFunction(S, DeclLoc, Best);
4001}
4002
4003/// Attempt initialization by constructor (C++ [dcl.init]), which
4004/// enumerates the constructors of the initialized entity and performs overload
4005/// resolution to select the best.
4006/// \param DestType The destination class type.
4007/// \param DestArrayType The destination type, which is either DestType or
4008/// a (possibly multidimensional) array of DestType.
4009/// \param IsListInit Is this list-initialization?
4010/// \param IsInitListCopy Is this non-list-initialization resulting from a
4011/// list-initialization from {x} where x is the same
4012/// type as the entity?
4013static void TryConstructorInitialization(Sema &S,
4014 const InitializedEntity &Entity,
4015 const InitializationKind &Kind,
4016 MultiExprArg Args, QualType DestType,
4017 QualType DestArrayType,
4018 InitializationSequence &Sequence,
4019 bool IsListInit = false,
4020 bool IsInitListCopy = false) {
4021 assert(((!IsListInit && !IsInitListCopy) ||
4022 (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
4023 "IsListInit/IsInitListCopy must come with a single initializer list "
4024 "argument.");
4025 InitListExpr *ILE =
4026 (IsListInit || IsInitListCopy) ? cast<InitListExpr>(Args[0]) : nullptr;
4027 MultiExprArg UnwrappedArgs =
4028 ILE ? MultiExprArg(ILE->getInits(), ILE->getNumInits()) : Args;
4029
4030 // The type we're constructing needs to be complete.
4031 if (!S.isCompleteType(Kind.getLocation(), DestType)) {
4032 Sequence.setIncompleteTypeFailure(DestType);
4033 return;
4034 }
4035
4036 // C++17 [dcl.init]p17:
4037 // - If the initializer expression is a prvalue and the cv-unqualified
4038 // version of the source type is the same class as the class of the
4039 // destination, the initializer expression is used to initialize the
4040 // destination object.
4041 // Per DR (no number yet), this does not apply when initializing a base
4042 // class or delegating to another constructor from a mem-initializer.
4043 // ObjC++: Lambda captured by the block in the lambda to block conversion
4044 // should avoid copy elision.
4045 if (S.getLangOpts().CPlusPlus17 &&
4046 Entity.getKind() != InitializedEntity::EK_Base &&
4047 Entity.getKind() != InitializedEntity::EK_Delegating &&
4048 Entity.getKind() !=
4049 InitializedEntity::EK_LambdaToBlockConversionBlockElement &&
4050 UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isRValue() &&
4051 S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
4052 // Convert qualifications if necessary.
4053 Sequence.AddQualificationConversionStep(DestType, VK_RValue);
4054 if (ILE)
4055 Sequence.RewrapReferenceInitList(DestType, ILE);
4056 return;
4057 }
4058
4059 const RecordType *DestRecordType = DestType->getAs<RecordType>();
4060 assert(DestRecordType && "Constructor initialization requires record type");
4061 CXXRecordDecl *DestRecordDecl
4062 = cast<CXXRecordDecl>(DestRecordType->getDecl());
4063
4064 // Build the candidate set directly in the initialization sequence
4065 // structure, so that it will persist if we fail.
4066 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4067
4068 // Determine whether we are allowed to call explicit constructors or
4069 // explicit conversion operators.
4070 bool AllowExplicit = Kind.AllowExplicit() || IsListInit;
4071 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;
4072
4073 // - Otherwise, if T is a class type, constructors are considered. The
4074 // applicable constructors are enumerated, and the best one is chosen
4075 // through overload resolution.
4076 DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl);
4077
4078 OverloadingResult Result = OR_No_Viable_Function;
4079 OverloadCandidateSet::iterator Best;
4080 bool AsInitializerList = false;
4081
4082 // C++11 [over.match.list]p1, per DR1467:
4083 // When objects of non-aggregate type T are list-initialized, such that
4084 // 8.5.4 [dcl.init.list] specifies that overload resolution is performed
4085 // according to the rules in this section, overload resolution selects
4086 // the constructor in two phases:
4087 //
4088 // - Initially, the candidate functions are the initializer-list
4089 // constructors of the class T and the argument list consists of the
4090 // initializer list as a single argument.
4091 if (IsListInit) {
4092 AsInitializerList = true;
4093
4094 // If the initializer list has no elements and T has a default constructor,
4095 // the first phase is omitted.
4096 if (!(UnwrappedArgs.empty() && S.LookupDefaultConstructor(DestRecordDecl)))
4097 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
4098 CandidateSet, DestType, Ctors, Best,
4099 CopyInitialization, AllowExplicit,
4100 /*OnlyListConstructors=*/true,
4101 IsListInit);
4102 }
4103
4104 // C++11 [over.match.list]p1:
4105 // - If no viable initializer-list constructor is found, overload resolution
4106 // is performed again, where the candidate functions are all the
4107 // constructors of the class T and the argument list consists of the
4108 // elements of the initializer list.
4109 if (Result == OR_No_Viable_Function) {
4110 AsInitializerList = false;
4111 Result = ResolveConstructorOverload(S, Kind.getLocation(), UnwrappedArgs,
4112 CandidateSet, DestType, Ctors, Best,
4113 CopyInitialization, AllowExplicit,
4114 /*OnlyListConstructors=*/false,
4115 IsListInit);
4116 }
4117 if (Result) {
4118 Sequence.SetOverloadFailure(
4119 IsListInit ? InitializationSequence::FK_ListConstructorOverloadFailed
4120 : InitializationSequence::FK_ConstructorOverloadFailed,
4121 Result);
4122
4123 if (Result != OR_Deleted)
4124 return;
4125 }
4126
4127 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4128
4129 // In C++17, ResolveConstructorOverload can select a conversion function
4130 // instead of a constructor.
4131 if (auto *CD = dyn_cast<CXXConversionDecl>(Best->Function)) {
4132 // Add the user-defined conversion step that calls the conversion function.
4133 QualType ConvType = CD->getConversionType();
4134 assert(S.Context.hasSameUnqualifiedType(ConvType, DestType) &&
4135 "should not have selected this conversion function");
4136 Sequence.AddUserConversionStep(CD, Best->FoundDecl, ConvType,
4137 HadMultipleCandidates);
4138 if (!S.Context.hasSameType(ConvType, DestType))
4139 Sequence.AddQualificationConversionStep(DestType, VK_RValue);
4140 if (IsListInit)
4141 Sequence.RewrapReferenceInitList(Entity.getType(), ILE);
4142 return;
4143 }
4144
4145 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
4146 if (Result != OR_Deleted) {
4147 // C++11 [dcl.init]p6:
4148 // If a program calls for the default initialization of an object
4149 // of a const-qualified type T, T shall be a class type with a
4150 // user-provided default constructor.
4151 // C++ core issue 253 proposal:
4152 // If the implicit default constructor initializes all subobjects, no
4153 // initializer should be required.
4154 // The 253 proposal is for example needed to process libstdc++ headers
4155 // in 5.x.
4156 if (Kind.getKind() == InitializationKind::IK_Default &&
4157 Entity.getType().isConstQualified()) {
4158 if (!CtorDecl->getParent()->allowConstDefaultInit()) {
4159 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
4160 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
4161 return;
4162 }
4163 }
4164
4165 // C++11 [over.match.list]p1:
4166 // In copy-list-initialization, if an explicit constructor is chosen, the
4167 // initializer is ill-formed.
4168 if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
4169 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
4170 return;
4171 }
4172 }
4173
4174 // [class.copy.elision]p3:
4175 // In some copy-initialization contexts, a two-stage overload resolution
4176 // is performed.
4177 // If the first overload resolution selects a deleted function, we also
4178 // need the initialization sequence to decide whether to perform the second
4179 // overload resolution.
4180 // For deleted functions in other contexts, there is no need to get the
4181 // initialization sequence.
4182 if (Result == OR_Deleted && Kind.getKind() != InitializationKind::IK_Copy)
4183 return;
4184
4185 // Add the constructor initialization step. Any cv-qualification conversion is
4186 // subsumed by the initialization.
4187 Sequence.AddConstructorInitializationStep(
4188 Best->FoundDecl, CtorDecl, DestArrayType, HadMultipleCandidates,
4189 IsListInit | IsInitListCopy, AsInitializerList);
4190}
4191
4192static bool
4193ResolveOverloadedFunctionForReferenceBinding(Sema &S,
4194 Expr *Initializer,
4195 QualType &SourceType,
4196 QualType &UnqualifiedSourceType,
4197 QualType UnqualifiedTargetType,
4198 InitializationSequence &Sequence) {
4199 if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
4200 S.Context.OverloadTy) {
4201 DeclAccessPair Found;
4202 bool HadMultipleCandidates = false;
4203 if (FunctionDecl *Fn
4204 = S.ResolveAddressOfOverloadedFunction(Initializer,
4205 UnqualifiedTargetType,
4206 false, Found,
4207 &HadMultipleCandidates)) {
4208 Sequence.AddAddressOverloadResolutionStep(Fn, Found,
4209 HadMultipleCandidates);
4210 SourceType = Fn->getType();
4211 UnqualifiedSourceType = SourceType.getUnqualifiedType();
4212 } else if (!UnqualifiedTargetType->isRecordType()) {
4213 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4214 return true;
4215 }
4216 }
4217 return false;
4218}
4219
4220static void TryReferenceInitializationCore(Sema &S,
4221 const InitializedEntity &Entity,
4222 const InitializationKind &Kind,
4223 Expr *Initializer,
4224 QualType cv1T1, QualType T1,
4225 Qualifiers T1Quals,
4226 QualType cv2T2, QualType T2,
4227 Qualifiers T2Quals,
4228 InitializationSequence &Sequence);
4229
4230static void TryValueInitialization(Sema &S,
4231 const InitializedEntity &Entity,
4232 const InitializationKind &Kind,
4233 InitializationSequence &Sequence,
4234 InitListExpr *InitList = nullptr);
4235
4236/// Attempt list initialization of a reference.
4237static void TryReferenceListInitialization(Sema &S,
4238 const InitializedEntity &Entity,
4239 const InitializationKind &Kind,
4240 InitListExpr *InitList,
4241 InitializationSequence &Sequence,
4242 bool TreatUnavailableAsInvalid) {
4243 // First, catch C++03 where this isn't possible.
4244 if (!S.getLangOpts().CPlusPlus11) {
4245 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4246 return;
4247 }
4248 // Can't reference initialize a compound literal.
4249 if (Entity.getKind() == InitializedEntity::EK_CompoundLiteralInit) {
4250 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4251 return;
4252 }
4253
4254 QualType DestType = Entity.getType();
4255 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4256 Qualifiers T1Quals;
4257 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4258
4259 // Reference initialization via an initializer list works thus:
4260 // If the initializer list consists of a single element that is
4261 // reference-related to the referenced type, bind directly to that element
4262 // (possibly creating temporaries).
4263 // Otherwise, initialize a temporary with the initializer list and
4264 // bind to that.
4265 if (InitList->getNumInits() == 1) {
4266 Expr *Initializer = InitList->getInit(0);
4267 QualType cv2T2 = S.getCompletedType(Initializer);
4268 Qualifiers T2Quals;
4269 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4270
4271 // If this fails, creating a temporary wouldn't work either.
4272 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4273 T1, Sequence))
4274 return;
4275
4276 SourceLocation DeclLoc = Initializer->getBeginLoc();
4277 Sema::ReferenceCompareResult RefRelationship
4278 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2);
4279 if (RefRelationship >= Sema::Ref_Related) {
4280 // Try to bind the reference here.
4281 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4282 T1Quals, cv2T2, T2, T2Quals, Sequence);
4283 if (Sequence)
4284 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4285 return;
4286 }
4287
4288 // Update the initializer if we've resolved an overloaded function.
4289 if (Sequence.step_begin() != Sequence.step_end())
4290 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4291 }
4292
4293 // Not reference-related. Create a temporary and bind to that.
4294 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1);
4295
4296 TryListInitialization(S, TempEntity, Kind, InitList, Sequence,
4297 TreatUnavailableAsInvalid);
4298 if (Sequence) {
4299 if (DestType->isRValueReferenceType() ||
4300 (T1Quals.hasConst() && !T1Quals.hasVolatile()))
4301 Sequence.AddReferenceBindingStep(cv1T1, /*BindingTemporary=*/true);
4302 else
4303 Sequence.SetFailed(
4304 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
4305 }
4306}
4307
4308/// Attempt list initialization (C++0x [dcl.init.list])
4309static void TryListInitialization(Sema &S,
4310 const InitializedEntity &Entity,
4311 const InitializationKind &Kind,
4312 InitListExpr *InitList,
4313 InitializationSequence &Sequence,
4314 bool TreatUnavailableAsInvalid) {
4315 QualType DestType = Entity.getType();
4316
4317 // C++ doesn't allow scalar initialization with more than one argument.
4318 // But C99 complex numbers are scalars and it makes sense there.
4319 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
4320 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
4321 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
4322 return;
4323 }
4324 if (DestType->isReferenceType()) {
4325 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence,
4326 TreatUnavailableAsInvalid);
4327 return;
4328 }
4329
4330 if (DestType->isRecordType() &&
4331 !S.isCompleteType(InitList->getBeginLoc(), DestType)) {
4332 Sequence.setIncompleteTypeFailure(DestType);
4333 return;
4334 }
4335
4336 // C++11 [dcl.init.list]p3, per DR1467:
4337 // - If T is a class type and the initializer list has a single element of
4338 // type cv U, where U is T or a class derived from T, the object is
4339 // initialized from that element (by copy-initialization for
4340 // copy-list-initialization, or by direct-initialization for
4341 // direct-list-initialization).
4342 // - Otherwise, if T is a character array and the initializer list has a
4343 // single element that is an appropriately-typed string literal
4344 // (8.5.2 [dcl.init.string]), initialization is performed as described
4345 // in that section.
4346 // - Otherwise, if T is an aggregate, [...] (continue below).
4347 if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) {
4348 if (DestType->isRecordType()) {
4349 QualType InitType = InitList->getInit(0)->getType();
4350 if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
4351 S.IsDerivedFrom(InitList->getBeginLoc(), InitType, DestType)) {
4352 Expr *InitListAsExpr = InitList;
4353 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4354 DestType, Sequence,
4355 /*InitListSyntax*/false,
4356 /*IsInitListCopy*/true);
4357 return;
4358 }
4359 }
4360 if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) {
4361 Expr *SubInit[1] = {InitList->getInit(0)};
4362 if (!isa<VariableArrayType>(DestAT) &&
4363 IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) {
4364 InitializationKind SubKind =
4365 Kind.getKind() == InitializationKind::IK_DirectList
4366 ? InitializationKind::CreateDirect(Kind.getLocation(),
4367 InitList->getLBraceLoc(),
4368 InitList->getRBraceLoc())
4369 : Kind;
4370 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4371 /*TopLevelOfInitList*/ true,
4372 TreatUnavailableAsInvalid);
4373
4374 // TryStringLiteralInitialization() (in InitializeFrom()) will fail if
4375 // the element is not an appropriately-typed string literal, in which
4376 // case we should proceed as in C++11 (below).
4377 if (Sequence) {
4378 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4379 return;
4380 }
4381 }
4382 }
4383 }
4384
4385 // C++11 [dcl.init.list]p3:
4386 // - If T is an aggregate, aggregate initialization is performed.
4387 if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
4388 (S.getLangOpts().CPlusPlus11 &&
4389 S.isStdInitializerList(DestType, nullptr))) {
4390 if (S.getLangOpts().CPlusPlus11) {
4391 // - Otherwise, if the initializer list has no elements and T is a
4392 // class type with a default constructor, the object is
4393 // value-initialized.
4394 if (InitList->getNumInits() == 0) {
4395 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
4396 if (S.LookupDefaultConstructor(RD)) {
4397 TryValueInitialization(S, Entity, Kind, Sequence, InitList);
4398 return;
4399 }
4400 }
4401
4402 // - Otherwise, if T is a specialization of std::initializer_list<E>,
4403 // an initializer_list object constructed [...]
4404 if (TryInitializerListConstruction(S, InitList, DestType, Sequence,
4405 TreatUnavailableAsInvalid))
4406 return;
4407
4408 // - Otherwise, if T is a class type, constructors are considered.
4409 Expr *InitListAsExpr = InitList;
4410 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4411 DestType, Sequence, /*InitListSyntax*/true);
4412 } else
4413 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
4414 return;
4415 }
4416
4417 if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
4418 InitList->getNumInits() == 1) {
4419 Expr *E = InitList->getInit(0);
4420
4421 // - Otherwise, if T is an enumeration with a fixed underlying type,
4422 // the initializer-list has a single element v, and the initialization
4423 // is direct-list-initialization, the object is initialized with the
4424 // value T(v); if a narrowing conversion is required to convert v to
4425 // the underlying type of T, the program is ill-formed.
4426 auto *ET = DestType->getAs<EnumType>();
4427 if (S.getLangOpts().CPlusPlus17 &&
4428 Kind.getKind() == InitializationKind::IK_DirectList &&
4429 ET && ET->getDecl()->isFixed() &&
4430 !S.Context.hasSameUnqualifiedType(E->getType(), DestType) &&
4431 (E->getType()->isIntegralOrEnumerationType() ||
4432 E->getType()->isFloatingType())) {
4433 // There are two ways that T(v) can work when T is an enumeration type.
4434 // If there is either an implicit conversion sequence from v to T or
4435 // a conversion function that can convert from v to T, then we use that.
4436 // Otherwise, if v is of integral, enumeration, or floating-point type,
4437 // it is converted to the enumeration type via its underlying type.
4438 // There is no overlap possible between these two cases (except when the
4439 // source value is already of the destination type), and the first
4440 // case is handled by the general case for single-element lists below.
4441 ImplicitConversionSequence ICS;
4442 ICS.setStandard();
4443 ICS.Standard.setAsIdentityConversion();
4444 if (!E->isRValue())
4445 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
4446 // If E is of a floating-point type, then the conversion is ill-formed
4447 // due to narrowing, but go through the motions in order to produce the
4448 // right diagnostic.
4449 ICS.Standard.Second = E->getType()->isFloatingType()
4450 ? ICK_Floating_Integral
4451 : ICK_Integral_Conversion;
4452 ICS.Standard.setFromType(E->getType());
4453 ICS.Standard.setToType(0, E->getType());
4454 ICS.Standard.setToType(1, DestType);
4455 ICS.Standard.setToType(2, DestType);
4456 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2),
4457 /*TopLevelOfInitList*/true);
4458 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4459 return;
4460 }
4461
4462 // - Otherwise, if the initializer list has a single element of type E
4463 // [...references are handled above...], the object or reference is
4464 // initialized from that element (by copy-initialization for
4465 // copy-list-initialization, or by direct-initialization for
4466 // direct-list-initialization); if a narrowing conversion is required
4467 // to convert the element to T, the program is ill-formed.
4468 //
4469 // Per core-24034, this is direct-initialization if we were performing
4470 // direct-list-initialization and copy-initialization otherwise.
4471 // We can't use InitListChecker for this, because it always performs
4472 // copy-initialization. This only matters if we might use an 'explicit'
4473 // conversion operator, or for the special case conversion of nullptr_t to
4474 // bool, so we only need to handle those cases.
4475 //
4476 // FIXME: Why not do this in all cases?
4477 Expr *Init = InitList->getInit(0);
4478 if (Init->getType()->isRecordType() ||
4479 (Init->getType()->isNullPtrType() && DestType->isBooleanType())) {
4480 InitializationKind SubKind =
4481 Kind.getKind() == InitializationKind::IK_DirectList
4482 ? InitializationKind::CreateDirect(Kind.getLocation(),
4483 InitList->getLBraceLoc(),
4484 InitList->getRBraceLoc())
4485 : Kind;
4486 Expr *SubInit[1] = { Init };
4487 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4488 /*TopLevelOfInitList*/true,
4489 TreatUnavailableAsInvalid);
4490 if (Sequence)
4491 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4492 return;
4493 }
4494 }
4495
4496 InitListChecker CheckInitList(S, Entity, InitList,
4497 DestType, /*VerifyOnly=*/true, TreatUnavailableAsInvalid);
4498 if (CheckInitList.HadError()) {
4499 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
4500 return;
4501 }
4502
4503 // Add the list initialization step with the built init list.
4504 Sequence.AddListInitializationStep(DestType);
4505}
4506
4507/// Try a reference initialization that involves calling a conversion
4508/// function.
4509static OverloadingResult TryRefInitWithConversionFunction(
4510 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
4511 Expr *Initializer, bool AllowRValues, bool IsLValueRef,
4512 InitializationSequence &Sequence) {
4513 QualType DestType = Entity.getType();
4514 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4515 QualType T1 = cv1T1.getUnqualifiedType();
4516 QualType cv2T2 = Initializer->getType();
4517 QualType T2 = cv2T2.getUnqualifiedType();
4518
4519 assert(!S.CompareReferenceRelationship(Initializer->getBeginLoc(), T1, T2) &&
4520 "Must have incompatible references when binding via conversion");
4521
4522 // Build the candidate set directly in the initialization sequence
4523 // structure, so that it will persist if we fail.
4524 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4525 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4526
4527 // Determine whether we are allowed to call explicit conversion operators.
4528 // Note that none of [over.match.copy], [over.match.conv], nor
4529 // [over.match.ref] permit an explicit constructor to be chosen when
4530 // initializing a reference, not even for direct-initialization.
4531 bool AllowExplicitCtors = false;
4532 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();
4533
4534 const RecordType *T1RecordType = nullptr;
4535 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
4536 S.isCompleteType(Kind.getLocation(), T1)) {
4537 // The type we're converting to is a class type. Enumerate its constructors
4538 // to see if there is a suitable conversion.
4539 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
4540
4541 for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) {
4542 auto Info = getConstructorInfo(D);
4543 if (!Info.Constructor)
4544 continue;
4545
4546 if (!Info.Constructor->isInvalidDecl() &&
4547 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
4548 if (Info.ConstructorTmpl)
4549 S.AddTemplateOverloadCandidate(
4550 Info.ConstructorTmpl, Info.FoundDecl,
4551 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
4552 /*SuppressUserConversions=*/true,
4553 /*PartialOverloading*/ false, AllowExplicitCtors);
4554 else
4555 S.AddOverloadCandidate(
4556 Info.Constructor, Info.FoundDecl, Initializer, CandidateSet,
4557 /*SuppressUserConversions=*/true,
4558 /*PartialOverloading*/ false, AllowExplicitCtors);
4559 }
4560 }
4561 }
4562 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
4563 return OR_No_Viable_Function;
4564
4565 const RecordType *T2RecordType = nullptr;
4566 if ((T2RecordType = T2->getAs<RecordType>()) &&
4567 S.isCompleteType(Kind.getLocation(), T2)) {
4568 // The type we're converting from is a class type, enumerate its conversion
4569 // functions.
4570 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
4571
4572 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4573 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4574 NamedDecl *D = *I;
4575 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4576 if (isa<UsingShadowDecl>(D))
4577 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4578
4579 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4580 CXXConversionDecl *Conv;
4581 if (ConvTemplate)
4582 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4583 else
4584 Conv = cast<CXXConversionDecl>(D);
4585
4586 // If the conversion function doesn't return a reference type,
4587 // it can't be considered for this conversion unless we're allowed to
4588 // consider rvalues.
4589 // FIXME: Do we need to make sure that we only consider conversion
4590 // candidates with reference-compatible results? That might be needed to
4591 // break recursion.
4592 if ((AllowRValues ||
4593 Conv->getConversionType()->isLValueReferenceType())) {
4594 if (ConvTemplate)
4595 S.AddTemplateConversionCandidate(
4596 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
4597 CandidateSet,
4598 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4599 else
4600 S.AddConversionCandidate(
4601 Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet,
4602 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4603 }
4604 }
4605 }
4606 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
4607 return OR_No_Viable_Function;
4608
4609 SourceLocation DeclLoc = Initializer->getBeginLoc();
4610
4611 // Perform overload resolution. If it fails, return the failed result.
4612 OverloadCandidateSet::iterator Best;
4613 if (OverloadingResult Result
4614 = CandidateSet.BestViableFunction(S, DeclLoc, Best))
4615 return Result;
4616
4617 FunctionDecl *Function = Best->Function;
4618 // This is the overload that will be used for this initialization step if we
4619 // use this initialization. Mark it as referenced.
4620 Function->setReferenced();
4621
4622 // Compute the returned type and value kind of the conversion.
4623 QualType cv3T3;
4624 if (isa<CXXConversionDecl>(Function))
4625 cv3T3 = Function->getReturnType();
4626 else
4627 cv3T3 = T1;
4628
4629 ExprValueKind VK = VK_RValue;
4630 if (cv3T3->isLValueReferenceType())
4631 VK = VK_LValue;
4632 else if (const auto *RRef = cv3T3->getAs<RValueReferenceType>())
4633 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
4634 cv3T3 = cv3T3.getNonLValueExprType(S.Context);
4635
4636 // Add the user-defined conversion step.
4637 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4638 Sequence.AddUserConversionStep(Function, Best->FoundDecl, cv3T3,
4639 HadMultipleCandidates);
4640
4641 // Determine whether we'll need to perform derived-to-base adjustments or
4642 // other conversions.
4643 Sema::ReferenceConversions RefConv;
4644 Sema::ReferenceCompareResult NewRefRelationship =
4645 S.CompareReferenceRelationship(DeclLoc, T1, cv3T3, &RefConv);
4646
4647 // Add the final conversion sequence, if necessary.
4648 if (NewRefRelationship == Sema::Ref_Incompatible) {
4649 assert(!isa<CXXConstructorDecl>(Function) &&
4650 "should not have conversion after constructor");
4651
4652 ImplicitConversionSequence ICS;
4653 ICS.setStandard();
4654 ICS.Standard = Best->FinalConversion;
4655 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2));
4656
4657 // Every implicit conversion results in a prvalue, except for a glvalue
4658 // derived-to-base conversion, which we handle below.
4659 cv3T3 = ICS.Standard.getToType(2);
4660 VK = VK_RValue;
4661 }
4662
4663 // If the converted initializer is a prvalue, its type T4 is adjusted to
4664 // type "cv1 T4" and the temporary materialization conversion is applied.
4665 //
4666 // We adjust the cv-qualifications to match the reference regardless of
4667 // whether we have a prvalue so that the AST records the change. In this
4668 // case, T4 is "cv3 T3".
4669 QualType cv1T4 = S.Context.getQualifiedType(cv3T3, cv1T1.getQualifiers());
4670 if (cv1T4.getQualifiers() != cv3T3.getQualifiers())
4671 Sequence.AddQualificationConversionStep(cv1T4, VK);
4672 Sequence.AddReferenceBindingStep(cv1T4, VK == VK_RValue);
4673 VK = IsLValueRef ? VK_LValue : VK_XValue;
4674
4675 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4676 Sequence.AddDerivedToBaseCastStep(cv1T1, VK);
4677 else if (RefConv & Sema::ReferenceConversions::ObjC)
4678 Sequence.AddObjCObjectConversionStep(cv1T1);
4679 else if (RefConv & Sema::ReferenceConversions::Function)
4680 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4681 else if (RefConv & Sema::ReferenceConversions::Qualification) {
4682 if (!S.Context.hasSameType(cv1T4, cv1T1))
4683 Sequence.AddQualificationConversionStep(cv1T1, VK);
4684 }
4685
4686 return OR_Success;
4687}
4688
4689static void CheckCXX98CompatAccessibleCopy(Sema &S,
4690 const InitializedEntity &Entity,
4691 Expr *CurInitExpr);
4692
4693/// Attempt reference initialization (C++0x [dcl.init.ref])
4694static void TryReferenceInitialization(Sema &S,
4695 const InitializedEntity &Entity,
4696 const InitializationKind &Kind,
4697 Expr *Initializer,
4698 InitializationSequence &Sequence) {
4699 QualType DestType = Entity.getType();
4700 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4701 Qualifiers T1Quals;
4702 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4703 QualType cv2T2 = S.getCompletedType(Initializer);
4704 Qualifiers T2Quals;
4705 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4706
4707 // If the initializer is the address of an overloaded function, try
4708 // to resolve the overloaded function. If all goes well, T2 is the
4709 // type of the resulting function.
4710 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4711 T1, Sequence))
4712 return;
4713
4714 // Delegate everything else to a subfunction.
4715 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4716 T1Quals, cv2T2, T2, T2Quals, Sequence);
4717}
4718
4719/// Determine whether an expression is a non-referenceable glvalue (one to
4720/// which a reference can never bind). Attempting to bind a reference to
4721/// such a glvalue will always create a temporary.
4722static bool isNonReferenceableGLValue(Expr *E) {
4723 return E->refersToBitField() || E->refersToVectorElement() ||
4724 E->refersToMatrixElement();
4725}
4726
4727/// Reference initialization without resolving overloaded functions.
4728///
4729/// We also can get here in C if we call a builtin which is declared as
4730/// a function with a parameter of reference type (such as __builtin_va_end()).
4731static void TryReferenceInitializationCore(Sema &S,
4732 const InitializedEntity &Entity,
4733 const InitializationKind &Kind,
4734 Expr *Initializer,
4735 QualType cv1T1, QualType T1,
4736 Qualifiers T1Quals,
4737 QualType cv2T2, QualType T2,
4738 Qualifiers T2Quals,
4739 InitializationSequence &Sequence) {
4740 QualType DestType = Entity.getType();
4741 SourceLocation DeclLoc = Initializer->getBeginLoc();
4742
4743 // Compute some basic properties of the types and the initializer.
4744 bool isLValueRef = DestType->isLValueReferenceType();
4745 bool isRValueRef = !isLValueRef;
4746 Expr::Classification InitCategory = Initializer->Classify(S.Context);
4747
4748 Sema::ReferenceConversions RefConv;
4749 Sema::ReferenceCompareResult RefRelationship =
4750 S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, &RefConv);
4751
4752 // C++0x [dcl.init.ref]p5:
4753 // A reference to type "cv1 T1" is initialized by an expression of type
4754 // "cv2 T2" as follows:
4755 //
4756 // - If the reference is an lvalue reference and the initializer
4757 // expression
4758 // Note the analogous bullet points for rvalue refs to functions. Because
4759 // there are no function rvalues in C++, rvalue refs to functions are treated
4760 // like lvalue refs.
4761 OverloadingResult ConvOvlResult = OR_Success;
4762 bool T1Function = T1->isFunctionType();
4763 if (isLValueRef || T1Function) {
4764 if (InitCategory.isLValue() && !isNonReferenceableGLValue(Initializer) &&
4765 (RefRelationship == Sema::Ref_Compatible ||
4766 (Kind.isCStyleOrFunctionalCast() &&
4767 RefRelationship == Sema::Ref_Related))) {
4768 // - is an lvalue (but is not a bit-field), and "cv1 T1" is
4769 // reference-compatible with "cv2 T2," or
4770 if (RefConv & (Sema::ReferenceConversions::DerivedToBase |
4771 Sema::ReferenceConversions::ObjC)) {
4772 // If we're converting the pointee, add any qualifiers first;
4773 // these qualifiers must all be top-level, so just convert to "cv1 T2".
4774 if (RefConv & (Sema::ReferenceConversions::Qualification))
4775 Sequence.AddQualificationConversionStep(
4776 S.Context.getQualifiedType(T2, T1Quals),
4777 Initializer->getValueKind());
4778 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4779 Sequence.AddDerivedToBaseCastStep(cv1T1, VK_LValue);
4780 else
4781 Sequence.AddObjCObjectConversionStep(cv1T1);
4782 } else if (RefConv & Sema::ReferenceConversions::Qualification) {
4783 // Perform a (possibly multi-level) qualification conversion.
4784 Sequence.AddQualificationConversionStep(cv1T1,
4785 Initializer->getValueKind());
4786 } else if (RefConv & Sema::ReferenceConversions::Function) {
4787 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4788 }
4789
4790 // We only create a temporary here when binding a reference to a
4791 // bit-field or vector element. Those cases are't supposed to be
4792 // handled by this bullet, but the outcome is the same either way.
4793 Sequence.AddReferenceBindingStep(cv1T1, false);
4794 return;
4795 }
4796
4797 // - has a class type (i.e., T2 is a class type), where T1 is not
4798 // reference-related to T2, and can be implicitly converted to an
4799 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
4800 // with "cv3 T3" (this conversion is selected by enumerating the
4801 // applicable conversion functions (13.3.1.6) and choosing the best
4802 // one through overload resolution (13.3)),
4803 // If we have an rvalue ref to function type here, the rhs must be
4804 // an rvalue. DR1287 removed the "implicitly" here.
4805 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
4806 (isLValueRef || InitCategory.isRValue())) {
4807 if (S.getLangOpts().CPlusPlus) {
4808 // Try conversion functions only for C++.
4809 ConvOvlResult = TryRefInitWithConversionFunction(
4810 S, Entity, Kind, Initializer, /*AllowRValues*/ isRValueRef,
4811 /*IsLValueRef*/ isLValueRef, Sequence);
4812 if (ConvOvlResult == OR_Success)
4813 return;
4814 if (ConvOvlResult != OR_No_Viable_Function)
4815 Sequence.SetOverloadFailure(
4816 InitializationSequence::FK_ReferenceInitOverloadFailed,
4817 ConvOvlResult);
4818 } else {
4819 ConvOvlResult = OR_No_Viable_Function;
4820 }
4821 }
4822 }
4823
4824 // - Otherwise, the reference shall be an lvalue reference to a
4825 // non-volatile const type (i.e., cv1 shall be const), or the reference
4826 // shall be an rvalue reference.
4827 // For address spaces, we interpret this to mean that an addr space
4828 // of a reference "cv1 T1" is a superset of addr space of "cv2 T2".
4829 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile() &&
4830 T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
4831 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
4832 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4833 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
4834 Sequence.SetOverloadFailure(
4835 InitializationSequence::FK_ReferenceInitOverloadFailed,
4836 ConvOvlResult);
4837 else if (!InitCategory.isLValue())
4838 Sequence.SetFailed(
4839 T1Quals.isAddressSpaceSupersetOf(T2Quals)
4840 ? InitializationSequence::
4841 FK_NonConstLValueReferenceBindingToTemporary
4842 : InitializationSequence::FK_ReferenceInitDropsQualifiers);
4843 else {
4844 InitializationSequence::FailureKind FK;
4845 switch (RefRelationship) {
4846 case Sema::Ref_Compatible:
4847 if (Initializer->refersToBitField())
4848 FK = InitializationSequence::
4849 FK_NonConstLValueReferenceBindingToBitfield;
4850 else if (Initializer->refersToVectorElement())
4851 FK = InitializationSequence::
4852 FK_NonConstLValueReferenceBindingToVectorElement;
4853 else if (Initializer->refersToMatrixElement())
4854 FK = InitializationSequence::
4855 FK_NonConstLValueReferenceBindingToMatrixElement;
4856 else
4857 llvm_unreachable("unexpected kind of compatible initializer");
4858 break;
4859 case Sema::Ref_Related:
4860 FK = InitializationSequence::FK_ReferenceInitDropsQualifiers;
4861 break;
4862 case Sema::Ref_Incompatible:
4863 FK = InitializationSequence::
4864 FK_NonConstLValueReferenceBindingToUnrelated;
4865 break;
4866 }
4867 Sequence.SetFailed(FK);
4868 }
4869 return;
4870 }
4871
4872 // - If the initializer expression
4873 // - is an
4874 // [<=14] xvalue (but not a bit-field), class prvalue, array prvalue, or
4875 // [1z] rvalue (but not a bit-field) or
4876 // function lvalue and "cv1 T1" is reference-compatible with "cv2 T2"
4877 //
4878 // Note: functions are handled above and below rather than here...
4879 if (!T1Function &&
4880 (RefRelationship == Sema::Ref_Compatible ||
4881 (Kind.isCStyleOrFunctionalCast() &&
4882 RefRelationship == Sema::Ref_Related)) &&
4883 ((InitCategory.isXValue() && !isNonReferenceableGLValue(Initializer)) ||
4884 (InitCategory.isPRValue() &&
4885 (S.getLangOpts().CPlusPlus17 || T2->isRecordType() ||
4886 T2->isArrayType())))) {
4887 ExprValueKind ValueKind = InitCategory.isXValue() ? VK_XValue : VK_RValue;
4888 if (InitCategory.isPRValue() && T2->isRecordType()) {
4889 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
4890 // compiler the freedom to perform a copy here or bind to the
4891 // object, while C++0x requires that we bind directly to the
4892 // object. Hence, we always bind to the object without making an
4893 // extra copy. However, in C++03 requires that we check for the
4894 // presence of a suitable copy constructor:
4895 //
4896 // The constructor that would be used to make the copy shall
4897 // be callable whether or not the copy is actually done.
4898 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
4899 Sequence.AddExtraneousCopyToTemporary(cv2T2);
4900 else if (S.getLangOpts().CPlusPlus11)
4901 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
4902 }
4903
4904 // C++1z [dcl.init.ref]/5.2.1.2:
4905 // If the converted initializer is a prvalue, its type T4 is adjusted
4906 // to type "cv1 T4" and the temporary materialization conversion is
4907 // applied.
4908 // Postpone address space conversions to after the temporary materialization
4909 // conversion to allow creating temporaries in the alloca address space.
4910 auto T1QualsIgnoreAS = T1Quals;
4911 auto T2QualsIgnoreAS = T2Quals;
4912 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
4913 T1QualsIgnoreAS.removeAddressSpace();
4914 T2QualsIgnoreAS.removeAddressSpace();
4915 }
4916 QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS);
4917 if (T1QualsIgnoreAS != T2QualsIgnoreAS)
4918 Sequence.AddQualificationConversionStep(cv1T4, ValueKind);
4919 Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_RValue);
4920 ValueKind = isLValueRef ? VK_LValue : VK_XValue;
4921 // Add addr space conversion if required.
4922 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
4923 auto T4Quals = cv1T4.getQualifiers();
4924 T4Quals.addAddressSpace(T1Quals.getAddressSpace());
4925 QualType cv1T4WithAS = S.Context.getQualifiedType(T2, T4Quals);
4926 Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind);
4927 cv1T4 = cv1T4WithAS;
4928 }
4929
4930 // In any case, the reference is bound to the resulting glvalue (or to
4931 // an appropriate base class subobject).
4932 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4933 Sequence.AddDerivedToBaseCastStep(cv1T1, ValueKind);
4934 else if (RefConv & Sema::ReferenceConversions::ObjC)
4935 Sequence.AddObjCObjectConversionStep(cv1T1);
4936 else if (RefConv & Sema::ReferenceConversions::Qualification) {
4937 if (!S.Context.hasSameType(cv1T4, cv1T1))
4938 Sequence.AddQualificationConversionStep(cv1T1, ValueKind);
4939 }
4940 return;
4941 }
4942
4943 // - has a class type (i.e., T2 is a class type), where T1 is not
4944 // reference-related to T2, and can be implicitly converted to an
4945 // xvalue, class prvalue, or function lvalue of type "cv3 T3",
4946 // where "cv1 T1" is reference-compatible with "cv3 T3",
4947 //
4948 // DR1287 removes the "implicitly" here.
4949 if (T2->isRecordType()) {
4950 if (RefRelationship == Sema::Ref_Incompatible) {
4951 ConvOvlResult = TryRefInitWithConversionFunction(
4952 S, Entity, Kind, Initializer, /*AllowRValues*/ true,
4953 /*IsLValueRef*/ isLValueRef, Sequence);
4954 if (ConvOvlResult)
4955 Sequence.SetOverloadFailure(
4956 InitializationSequence::FK_ReferenceInitOverloadFailed,
4957 ConvOvlResult);
4958
4959 return;
4960 }
4961
4962 if (RefRelationship == Sema::Ref_Compatible &&
4963 isRValueRef && InitCategory.isLValue()) {
4964 Sequence.SetFailed(
4965 InitializationSequence::FK_RValueReferenceBindingToLValue);
4966 return;
4967 }
4968
4969 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
4970 return;
4971 }
4972
4973 // - Otherwise, a temporary of type "cv1 T1" is created and initialized
4974 // from the initializer expression using the rules for a non-reference
4975 // copy-initialization (8.5). The reference is then bound to the
4976 // temporary. [...]
4977
4978 // Ignore address space of reference type at this point and perform address
4979 // space conversion after the reference binding step.
4980 QualType cv1T1IgnoreAS =
4981 T1Quals.hasAddressSpace()
4982 ? S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace())
4983 : cv1T1;
4984
4985 InitializedEntity TempEntity =
4986 InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);
4987
4988 // FIXME: Why do we use an implicit conversion here rather than trying
4989 // copy-initialization?
4990 ImplicitConversionSequence ICS
4991 = S.TryImplicitConversion(Initializer, TempEntity.getType(),
4992 /*SuppressUserConversions=*/false,
4993 Sema::AllowedExplicit::None,
4994 /*FIXME:InOverloadResolution=*/false,
4995 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
4996 /*AllowObjCWritebackConversion=*/false);
4997
4998 if (ICS.isBad()) {
4999 // FIXME: Use the conversion function set stored in ICS to turn
5000 // this into an overloading ambiguity diagnostic. However, we need
5001 // to keep that set as an OverloadCandidateSet rather than as some
5002 // other kind of set.
5003 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
5004 Sequence.SetOverloadFailure(
5005 InitializationSequence::FK_ReferenceInitOverloadFailed,
5006 ConvOvlResult);
5007 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
5008 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
5009 else
5010 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
5011 return;
5012 } else {
5013 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
5014 }
5015
5016 // [...] If T1 is reference-related to T2, cv1 must be the
5017 // same cv-qualification as, or greater cv-qualification
5018 // than, cv2; otherwise, the program is ill-formed.
5019 unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
5020 unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
5021 if ((RefRelationship == Sema::Ref_Related &&
5022 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) ||
5023 !T1Quals.isAddressSpaceSupersetOf(T2Quals)) {
5024 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
5025 return;
5026 }
5027
5028 // [...] If T1 is reference-related to T2 and the reference is an rvalue
5029 // reference, the initializer expression shall not be an lvalue.
5030 if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
5031 InitCategory.isLValue()) {
5032 Sequence.SetFailed(
5033 InitializationSequence::FK_RValueReferenceBindingToLValue);
5034 return;
5035 }
5036
5037 Sequence.AddReferenceBindingStep(cv1T1IgnoreAS, /*BindingTemporary=*/true);
5038
5039 if (T1Quals.hasAddressSpace()) {
5040 if (!Qualifiers::isAddressSpaceSupersetOf(T1Quals.getAddressSpace(),
5041 LangAS::Default)) {
5042 Sequence.SetFailed(
5043 InitializationSequence::FK_ReferenceAddrspaceMismatchTemporary);
5044 return;
5045 }
5046 Sequence.AddQualificationConversionStep(cv1T1, isLValueRef ? VK_LValue
5047 : VK_XValue);
5048 }
5049}
5050
5051/// Attempt character array initialization from a string literal
5052/// (C++ [dcl.init.string], C99 6.7.8).
5053static void TryStringLiteralInitialization(Sema &S,
5054 const InitializedEntity &Entity,
5055 const InitializationKind &Kind,
5056 Expr *Initializer,
5057 InitializationSequence &Sequence) {
5058 Sequence.AddStringInitStep(Entity.getType());
5059}
5060
5061/// Attempt value initialization (C++ [dcl.init]p7).
5062static void TryValueInitialization(Sema &S,
5063 const InitializedEntity &Entity,
5064 const InitializationKind &Kind,
5065 InitializationSequence &Sequence,
5066 InitListExpr *InitList) {
5067 assert((!InitList || InitList->getNumInits() == 0) &&
5068 "Shouldn't use value-init for non-empty init lists");
5069
5070 // C++98 [dcl.init]p5, C++11 [dcl.init]p7:
5071 //
5072 // To value-initialize an object of type T means:
5073 QualType T = Entity.getType();
5074
5075 // -- if T is an array type, then each element is value-initialized;
5076 T = S.Context.getBaseElementType(T);
5077
5078 if (const RecordType *RT = T->getAs<RecordType>()) {
5079 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
5080 bool NeedZeroInitialization = true;
5081 // C++98:
5082 // -- if T is a class type (clause 9) with a user-declared constructor
5083 // (12.1), then the default constructor for T is called (and the
5084 // initialization is ill-formed if T has no accessible default
5085 // constructor);
5086 // C++11:
5087 // -- if T is a class type (clause 9) with either no default constructor
5088 // (12.1 [class.ctor]) or a default constructor that is user-provided
5089 // or deleted, then the object is default-initialized;
5090 //
5091 // Note that the C++11 rule is the same as the C++98 rule if there are no
5092 // defaulted or deleted constructors, so we just use it unconditionally.
5093 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
5094 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
5095 NeedZeroInitialization = false;
5096
5097 // -- if T is a (possibly cv-qualified) non-union class type without a
5098 // user-provided or deleted default constructor, then the object is
5099 // zero-initialized and, if T has a non-trivial default constructor,
5100 // default-initialized;
5101 // The 'non-union' here was removed by DR1502. The 'non-trivial default
5102 // constructor' part was removed by DR1507.
5103 if (NeedZeroInitialization)
5104 Sequence.AddZeroInitializationStep(Entity.getType());
5105
5106 // C++03:
5107 // -- if T is a non-union class type without a user-declared constructor,
5108 // then every non-static data member and base class component of T is
5109 // value-initialized;
5110 // [...] A program that calls for [...] value-initialization of an
5111 // entity of reference type is ill-formed.
5112 //
5113 // C++11 doesn't need this handling, because value-initialization does not
5114 // occur recursively there, and the implicit default constructor is
5115 // defined as deleted in the problematic cases.
5116 if (!S.getLangOpts().CPlusPlus11 &&
5117 ClassDecl->hasUninitializedReferenceMember()) {
5118 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
5119 return;
5120 }
5121
5122 // If this is list-value-initialization, pass the empty init list on when
5123 // building the constructor call. This affects the semantics of a few
5124 // things (such as whether an explicit default constructor can be called).
5125 Expr *InitListAsExpr = InitList;
5126 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
5127 bool InitListSyntax = InitList;
5128
5129 // FIXME: Instead of creating a CXXConstructExpr of array type here,
5130 // wrap a class-typed CXXConstructExpr in an ArrayInitLoopExpr.
5131 return TryConstructorInitialization(
5132 S, Entity, Kind, Args, T, Entity.getType(), Sequence, InitListSyntax);
5133 }
5134 }
5135
5136 Sequence.AddZeroInitializationStep(Entity.getType());
5137}
5138
5139/// Attempt default initialization (C++ [dcl.init]p6).
5140static void TryDefaultInitialization(Sema &S,
5141 const InitializedEntity &Entity,
5142 const InitializationKind &Kind,
5143 InitializationSequence &Sequence) {
5144 assert(Kind.getKind() == InitializationKind::IK_Default);
5145
5146 // C++ [dcl.init]p6:
5147 // To default-initialize an object of type T means:
5148 // - if T is an array type, each element is default-initialized;
5149 QualType DestType = S.Context.getBaseElementType(Entity.getType());
5150
5151 // - if T is a (possibly cv-qualified) class type (Clause 9), the default
5152 // constructor for T is called (and the initialization is ill-formed if
5153 // T has no accessible default constructor);
5154 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
5155 TryConstructorInitialization(S, Entity, Kind, None, DestType,
5156 Entity.getType(), Sequence);
5157 return;
5158 }
5159
5160 // - otherwise, no initialization is performed.
5161
5162 // If a program calls for the default initialization of an object of
5163 // a const-qualified type T, T shall be a class type with a user-provided
5164 // default constructor.
5165 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
5166 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
5167 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
5168 return;
5169 }
5170
5171 // If the destination type has a lifetime property, zero-initialize it.
5172 if (DestType.getQualifiers().hasObjCLifetime()) {
5173 Sequence.AddZeroInitializationStep(Entity.getType());
5174 return;
5175 }
5176}
5177
5178/// Attempt a user-defined conversion between two types (C++ [dcl.init]),
5179/// which enumerates all conversion functions and performs overload resolution
5180/// to select the best.
5181static void TryUserDefinedConversion(Sema &S,
5182 QualType DestType,
5183 const InitializationKind &Kind,
5184 Expr *Initializer,
5185 InitializationSequence &Sequence,
5186 bool TopLevelOfInitList) {
5187 assert(!DestType->isReferenceType() && "References are handled elsewhere");
5188 QualType SourceType = Initializer->getType();
5189 assert((DestType->isRecordType() || SourceType->isRecordType()) &&
5190 "Must have a class type to perform a user-defined conversion");
5191
5192 // Build the candidate set directly in the initialization sequence
5193 // structure, so that it will persist if we fail.
5194 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
5195 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
5196 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
5197
5198 // Determine whether we are allowed to call explicit constructors or
5199 // explicit conversion operators.
5200 bool AllowExplicit = Kind.AllowExplicit();
5201
5202 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
5203 // The type we're converting to is a class type. Enumerate its constructors
5204 // to see if there is a suitable conversion.
5205 CXXRecordDecl *DestRecordDecl
5206 = cast<CXXRecordDecl>(DestRecordType->getDecl());
5207
5208 // Try to complete the type we're converting to.
5209 if (S.isCompleteType(Kind.getLocation(), DestType)) {
5210 for (NamedDecl *D : S.LookupConstructors(DestRecordDecl)) {
5211 auto Info = getConstructorInfo(D);
5212 if (!Info.Constructor)
5213 continue;
5214
5215 if (!Info.Constructor->isInvalidDecl() &&
5216 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
5217 if (Info.ConstructorTmpl)
5218 S.AddTemplateOverloadCandidate(
5219 Info.ConstructorTmpl, Info.FoundDecl,
5220 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
5221 /*SuppressUserConversions=*/true,
5222 /*PartialOverloading*/ false, AllowExplicit);
5223 else
5224 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
5225 Initializer, CandidateSet,
5226 /*SuppressUserConversions=*/true,
5227 /*PartialOverloading*/ false, AllowExplicit);
5228 }
5229 }
5230 }
5231 }
5232
5233 SourceLocation DeclLoc = Initializer->getBeginLoc();
5234
5235 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
5236 // The type we're converting from is a class type, enumerate its conversion
5237 // functions.
5238
5239 // We can only enumerate the conversion functions for a complete type; if
5240 // the type isn't complete, simply skip this step.
5241 if (S.isCompleteType(DeclLoc, SourceType)) {
5242 CXXRecordDecl *SourceRecordDecl
5243 = cast<CXXRecordDecl>(SourceRecordType->getDecl());
5244
5245 const auto &Conversions =
5246 SourceRecordDecl->getVisibleConversionFunctions();
5247 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5248 NamedDecl *D = *I;
5249 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
5250 if (isa<UsingShadowDecl>(D))
5251 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5252
5253 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5254 CXXConversionDecl *Conv;
5255 if (ConvTemplate)
5256 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5257 else
5258 Conv = cast<CXXConversionDecl>(D);
5259
5260 if (ConvTemplate)
5261 S.AddTemplateConversionCandidate(
5262 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
5263 CandidateSet, AllowExplicit, AllowExplicit);
5264 else
5265 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
5266 DestType, CandidateSet, AllowExplicit,
5267 AllowExplicit);
5268 }
5269 }
5270 }
5271
5272 // Perform overload resolution. If it fails, return the failed result.
5273 OverloadCandidateSet::iterator Best;
5274 if (OverloadingResult Result
5275 = CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
5276 Sequence.SetOverloadFailure(
5277 InitializationSequence::FK_UserConversionOverloadFailed, Result);
5278
5279 // [class.copy.elision]p3:
5280 // In some copy-initialization contexts, a two-stage overload resolution
5281 // is performed.
5282 // If the first overload resolution selects a deleted function, we also
5283 // need the initialization sequence to decide whether to perform the second
5284 // overload resolution.
5285 if (!(Result == OR_Deleted &&
5286 Kind.getKind() == InitializationKind::IK_Copy))
5287 return;
5288 }
5289
5290 FunctionDecl *Function = Best->Function;
5291 Function->setReferenced();
5292 bool HadMultipleCandidates = (CandidateSet.size() > 1);
5293
5294 if (isa<CXXConstructorDecl>(Function)) {
5295 // Add the user-defined conversion step. Any cv-qualification conversion is
5296 // subsumed by the initialization. Per DR5, the created temporary is of the
5297 // cv-unqualified type of the destination.
5298 Sequence.AddUserConversionStep(Function, Best->FoundDecl,
5299 DestType.getUnqualifiedType(),
5300 HadMultipleCandidates);
5301
5302 // C++14 and before:
5303 // - if the function is a constructor, the call initializes a temporary
5304 // of the cv-unqualified version of the destination type. The [...]
5305 // temporary [...] is then used to direct-initialize, according to the
5306 // rules above, the object that is the destination of the
5307 // copy-initialization.
5308 // Note that this just performs a simple object copy from the temporary.
5309 //
5310 // C++17:
5311 // - if the function is a constructor, the call is a prvalue of the
5312 // cv-unqualified version of the destination type whose return object
5313 // is initialized by the constructor. The call is used to
5314 // direct-initialize, according to the rules above, the object that
5315 // is the destination of the copy-initialization.
5316 // Therefore we need to do nothing further.
5317 //
5318 // FIXME: Mark this copy as extraneous.
5319 if (!S.getLangOpts().CPlusPlus17)
5320 Sequence.AddFinalCopy(DestType);
5321 else if (DestType.hasQualifiers())
5322 Sequence.AddQualificationConversionStep(DestType, VK_RValue);
5323 return;
5324 }
5325
5326 // Add the user-defined conversion step that calls the conversion function.
5327 QualType ConvType = Function->getCallResultType();
5328 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
5329 HadMultipleCandidates);
5330
5331 if (ConvType->getAs<RecordType>()) {
5332 // The call is used to direct-initialize [...] the object that is the
5333 // destination of the copy-initialization.
5334 //
5335 // In C++17, this does not call a constructor if we enter /17.6.1:
5336 // - If the initializer expression is a prvalue and the cv-unqualified
5337 // version of the source type is the same as the class of the
5338 // destination [... do not make an extra copy]
5339 //
5340 // FIXME: Mark this copy as extraneous.
5341 if (!S.getLangOpts().CPlusPlus17 ||
5342 Function->getReturnType()->isReferenceType() ||
5343 !S.Context.hasSameUnqualifiedType(ConvType, DestType))
5344 Sequence.AddFinalCopy(DestType);
5345 else if (!S.Context.hasSameType(ConvType, DestType))
5346 Sequence.AddQualificationConversionStep(DestType, VK_RValue);
5347 return;
5348 }
5349
5350 // If the conversion following the call to the conversion function
5351 // is interesting, add it as a separate step.
5352 if (Best->FinalConversion.First || Best->FinalConversion.Second ||
5353 Best->FinalConversion.Third) {
5354 ImplicitConversionSequence ICS;
5355 ICS.setStandard();
5356 ICS.Standard = Best->FinalConversion;
5357 Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
5358 }
5359}
5360
5361/// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
5362/// a function with a pointer return type contains a 'return false;' statement.
5363/// In C++11, 'false' is not a null pointer, so this breaks the build of any
5364/// code using that header.
5365///
5366/// Work around this by treating 'return false;' as zero-initializing the result
5367/// if it's used in a pointer-returning function in a system header.
5368static bool isLibstdcxxPointerReturnFalseHack(Sema &S,
5369 const InitializedEntity &Entity,
5370 const Expr *Init) {
5371 return S.getLangOpts().CPlusPlus11 &&
5372 Entity.getKind() == InitializedEntity::EK_Result &&
5373 Entity.getType()->isPointerType() &&
5374 isa<CXXBoolLiteralExpr>(Init) &&
5375 !cast<CXXBoolLiteralExpr>(Init)->getValue() &&
5376 S.getSourceManager().isInSystemHeader(Init->getExprLoc());
5377}
5378
5379/// The non-zero enum values here are indexes into diagnostic alternatives.
5380enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };
5381
5382/// Determines whether this expression is an acceptable ICR source.
5383static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
5384 bool isAddressOf, bool &isWeakAccess) {
5385 // Skip parens.
5386 e = e->IgnoreParens();
5387
5388 // Skip address-of nodes.
5389 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
5390 if (op->getOpcode() == UO_AddrOf)
5391 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
5392 isWeakAccess);
5393
5394 // Skip certain casts.
5395 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
5396 switch (ce->getCastKind()) {
5397 case CK_Dependent:
5398 case CK_BitCast:
5399 case CK_LValueBitCast:
5400 case CK_NoOp:
5401 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);
5402
5403 case CK_ArrayToPointerDecay:
5404 return IIK_nonscalar;
5405
5406 case CK_NullToPointer:
5407 return IIK_okay;
5408
5409 default:
5410 break;
5411 }
5412
5413 // If we have a declaration reference, it had better be a local variable.
5414 } else if (isa<DeclRefExpr>(e)) {
5415 // set isWeakAccess to true, to mean that there will be an implicit
5416 // load which requires a cleanup.
5417 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
5418 isWeakAccess = true;
5419
5420 if (!isAddressOf) return IIK_nonlocal;
5421
5422 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
5423 if (!var) return IIK_nonlocal;
5424
5425 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);
5426
5427 // If we have a conditional operator, check both sides.
5428 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
5429 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
5430 isWeakAccess))
5431 return iik;
5432
5433 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);
5434
5435 // These are never scalar.
5436 } else if (isa<ArraySubscriptExpr>(e)) {
5437 return IIK_nonscalar;
5438
5439 // Otherwise, it needs to be a null pointer constant.
5440 } else {
5441 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
5442 ? IIK_okay : IIK_nonlocal);
5443 }
5444
5445 return IIK_nonlocal;
5446}
5447
5448/// Check whether the given expression is a valid operand for an
5449/// indirect copy/restore.
5450static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
5451 assert(src->isRValue());
5452 bool isWeakAccess = false;
5453 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
5454 // If isWeakAccess to true, there will be an implicit
5455 // load which requires a cleanup.
5456 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
5457 S.Cleanup.setExprNeedsCleanups(true);
5458
5459 if (iik == IIK_okay) return;
5460
5461 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
5462 << ((unsigned) iik - 1) // shift index into diagnostic explanations
5463 << src->getSourceRange();
5464}
5465
5466/// Determine whether we have compatible array types for the
5467/// purposes of GNU by-copy array initialization.
5468static bool hasCompatibleArrayTypes(ASTContext &Context, const ArrayType *Dest,
5469 const ArrayType *Source) {
5470 // If the source and destination array types are equivalent, we're
5471 // done.
5472 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
5473 return true;
5474
5475 // Make sure that the element types are the same.
5476 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
5477 return false;
5478
5479 // The only mismatch we allow is when the destination is an
5480 // incomplete array type and the source is a constant array type.
5481 return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
5482}
5483
5484static bool tryObjCWritebackConversion(Sema &S,
5485 InitializationSequence &Sequence,
5486 const InitializedEntity &Entity,
5487 Expr *Initializer) {
5488 bool ArrayDecay = false;
5489 QualType ArgType = Initializer->getType();
5490 QualType ArgPointee;
5491 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
5492 ArrayDecay = true;
5493 ArgPointee = ArgArrayType->getElementType();
5494 ArgType = S.Context.getPointerType(ArgPointee);
5495 }
5496
5497 // Handle write-back conversion.
5498 QualType ConvertedArgType;
5499 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
5500 ConvertedArgType))
5501 return false;
5502
5503 // We should copy unless we're passing to an argument explicitly
5504 // marked 'out'.
5505 bool ShouldCopy = true;
5506 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
5507 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
5508
5509 // Do we need an lvalue conversion?
5510 if (ArrayDecay || Initializer->isGLValue()) {
5511 ImplicitConversionSequence ICS;
5512 ICS.setStandard();
5513 ICS.Standard.setAsIdentityConversion();
5514
5515 QualType ResultType;
5516 if (ArrayDecay) {
5517 ICS.Standard.First = ICK_Array_To_Pointer;
5518 ResultType = S.Context.getPointerType(ArgPointee);
5519 } else {
5520 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
5521 ResultType = Initializer->getType().getNonLValueExprType(S.Context);
5522 }
5523
5524 Sequence.AddConversionSequenceStep(ICS, ResultType);
5525 }
5526
5527 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
5528 return true;
5529}
5530
5531static bool TryOCLSamplerInitialization(Sema &S,
5532 InitializationSequence &Sequence,
5533 QualType DestType,
5534 Expr *Initializer) {
5535 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
5536 (!Initializer->isIntegerConstantExpr(S.Context) &&
5537 !Initializer->getType()->isSamplerT()))
5538 return false;
5539
5540 Sequence.AddOCLSamplerInitStep(DestType);
5541 return true;
5542}
5543
5544static bool IsZeroInitializer(Expr *Initializer, Sema &S) {
5545 return Initializer->isIntegerConstantExpr(S.getASTContext()) &&
5546 (Initializer->EvaluateKnownConstInt(S.getASTContext()) == 0);
5547}
5548
5549static bool TryOCLZeroOpaqueTypeInitialization(Sema &S,
5550 InitializationSequence &Sequence,
5551 QualType DestType,
5552 Expr *Initializer) {
5553 if (!S.getLangOpts().OpenCL)
5554 return false;
5555
5556 //
5557 // OpenCL 1.2 spec, s6.12.10
5558 //
5559 // The event argument can also be used to associate the
5560 // async_work_group_copy with a previous async copy allowing
5561 // an event to be shared by multiple async copies; otherwise
5562 // event should be zero.
5563 //
5564 if (DestType->isEventT() || DestType->isQueueT()) {
5565 if (!IsZeroInitializer(Initializer, S))
5566 return false;
5567
5568 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5569 return true;
5570 }
5571
5572 // We should allow zero initialization for all types defined in the
5573 // cl_intel_device_side_avc_motion_estimation extension, except
5574 // intel_sub_group_avc_mce_payload_t and intel_sub_group_avc_mce_result_t.
5575 if (S.getOpenCLOptions().isEnabled(
5576 "cl_intel_device_side_avc_motion_estimation") &&
5577 DestType->isOCLIntelSubgroupAVCType()) {
5578 if (DestType->isOCLIntelSubgroupAVCMcePayloadType() ||
5579 DestType->isOCLIntelSubgroupAVCMceResultType())
5580 return false;
5581 if (!IsZeroInitializer(Initializer, S))
5582 return false;
5583
5584 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5585 return true;
5586 }
5587
5588 return false;
5589}
5590
5591InitializationSequence::InitializationSequence(
5592 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
5593 MultiExprArg Args, bool TopLevelOfInitList, bool TreatUnavailableAsInvalid)
5594 : FailedOverloadResult(OR_Success),
5595 FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
5596 InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList,
5597 TreatUnavailableAsInvalid);
5598}
5599
5600/// Tries to get a FunctionDecl out of `E`. If it succeeds and we can take the
5601/// address of that function, this returns true. Otherwise, it returns false.
5602static bool isExprAnUnaddressableFunction(Sema &S, const Expr *E) {
5603 auto *DRE = dyn_cast<DeclRefExpr>(E);
5604 if (!DRE || !isa<FunctionDecl>(DRE->getDecl()))
5605 return false;
5606
5607 return !S.checkAddressOfFunctionIsAvailable(
5608 cast<FunctionDecl>(DRE->getDecl()));
5609}
5610
5611/// Determine whether we can perform an elementwise array copy for this kind
5612/// of entity.
5613static bool canPerformArrayCopy(const InitializedEntity &Entity) {
5614 switch (Entity.getKind()) {
5615 case InitializedEntity::EK_LambdaCapture:
5616 // C++ [expr.prim.lambda]p24:
5617 // For array members, the array elements are direct-initialized in
5618 // increasing subscript order.
5619 return true;
5620
5621 case InitializedEntity::EK_Variable:
5622 // C++ [dcl.decomp]p1:
5623 // [...] each element is copy-initialized or direct-initialized from the
5624 // corresponding element of the assignment-expression [...]
5625 return isa<DecompositionDecl>(Entity.getDecl());
5626
5627 case InitializedEntity::EK_Member:
5628 // C++ [class.copy.ctor]p14:
5629 // - if the member is an array, each element is direct-initialized with
5630 // the corresponding subobject of x
5631 return Entity.isImplicitMemberInitializer();
5632
5633 case InitializedEntity::EK_ArrayElement:
5634 // All the above cases are intended to apply recursively, even though none
5635 // of them actually say that.
5636 if (auto *E = Entity.getParent())
5637 return canPerformArrayCopy(*E);
5638 break;
5639
5640 default:
5641 break;
5642 }
5643
5644 return false;
5645}
5646
5647void InitializationSequence::InitializeFrom(Sema &S,
5648 const InitializedEntity &Entity,
5649 const InitializationKind &Kind,
5650 MultiExprArg Args,
5651 bool TopLevelOfInitList,
5652 bool TreatUnavailableAsInvalid) {
5653 ASTContext &Context = S.Context;
5654
5655 // Eliminate non-overload placeholder types in the arguments. We
5656 // need to do this before checking whether types are dependent
5657 // because lowering a pseudo-object expression might well give us
5658 // something of dependent type.
5659 for (unsigned I = 0, E = Args.size(); I != E; ++I)
5660 if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
5661 // FIXME: should we be doing this here?
5662 ExprResult result = S.CheckPlaceholderExpr(Args[I]);
5663 if (result.isInvalid()) {
5664 SetFailed(FK_PlaceholderType);
5665 return;
5666 }
5667 Args[I] = result.get();
5668 }
5669
5670 // C++0x [dcl.init]p16:
5671 // The semantics of initializers are as follows. The destination type is
5672 // the type of the object or reference being initialized and the source
5673 // type is the type of the initializer expression. The source type is not
5674 // defined when the initializer is a braced-init-list or when it is a
5675 // parenthesized list of expressions.
5676 QualType DestType = Entity.getType();
5677
5678 if (DestType->isDependentType() ||
5679 Expr::hasAnyTypeDependentArguments(Args)) {
5680 SequenceKind = DependentSequence;
5681 return;
5682 }
5683
5684 // Almost everything is a normal sequence.
5685 setSequenceKind(NormalSequence);
5686
5687 QualType SourceType;
5688 Expr *Initializer = nullptr;
5689 if (Args.size() == 1) {
5690 Initializer = Args[0];
5691 if (S.getLangOpts().ObjC) {
5692 if (S.CheckObjCBridgeRelatedConversions(Initializer->getBeginLoc(),
5693 DestType, Initializer->getType(),
5694 Initializer) ||
5695 S.CheckConversionToObjCLiteral(DestType, Initializer))
5696 Args[0] = Initializer;
5697 }
5698 if (!isa<InitListExpr>(Initializer))
5699 SourceType = Initializer->getType();
5700 }
5701
5702 // - If the initializer is a (non-parenthesized) braced-init-list, the
5703 // object is list-initialized (8.5.4).
5704 if (Kind.getKind() != InitializationKind::IK_Direct) {
5705 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
5706 TryListInitialization(S, Entity, Kind, InitList, *this,
5707 TreatUnavailableAsInvalid);
5708 return;
5709 }
5710 }
5711
5712 // - If the destination type is a reference type, see 8.5.3.
5713 if (DestType->isReferenceType()) {
5714 // C++0x [dcl.init.ref]p1:
5715 // A variable declared to be a T& or T&&, that is, "reference to type T"
5716 // (8.3.2), shall be initialized by an object, or function, of type T or
5717 // by an object that can be converted into a T.
5718 // (Therefore, multiple arguments are not permitted.)
5719 if (Args.size() != 1)
5720 SetFailed(FK_TooManyInitsForReference);
5721 // C++17 [dcl.init.ref]p5:
5722 // A reference [...] is initialized by an expression [...] as follows:
5723 // If the initializer is not an expression, presumably we should reject,
5724 // but the standard fails to actually say so.
5725 else if (isa<InitListExpr>(Args[0]))
5726 SetFailed(FK_ParenthesizedListInitForReference);
5727 else
5728 TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
5729 return;
5730 }
5731
5732 // - If the initializer is (), the object is value-initialized.
5733 if (Kind.getKind() == InitializationKind::IK_Value ||
5734 (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) {
5735 TryValueInitialization(S, Entity, Kind, *this);
5736 return;
5737 }
5738
5739 // Handle default initialization.
5740 if (Kind.getKind() == InitializationKind::IK_Default) {
5741 TryDefaultInitialization(S, Entity, Kind, *this);
5742 return;
5743 }
5744
5745 // - If the destination type is an array of characters, an array of
5746 // char16_t, an array of char32_t, or an array of wchar_t, and the
5747 // initializer is a string literal, see 8.5.2.
5748 // - Otherwise, if the destination type is an array, the program is
5749 // ill-formed.
5750 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
5751 if (Initializer && isa<VariableArrayType>(DestAT)) {
5752 SetFailed(FK_VariableLengthArrayHasInitializer);
5753 return;
5754 }
5755
5756 if (Initializer) {
5757 switch (IsStringInit(Initializer, DestAT, Context)) {
5758 case SIF_None:
5759 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
5760 return;
5761 case SIF_NarrowStringIntoWideChar:
5762 SetFailed(FK_NarrowStringIntoWideCharArray);
5763 return;
5764 case SIF_WideStringIntoChar:
5765 SetFailed(FK_WideStringIntoCharArray);
5766 return;
5767 case SIF_IncompatWideStringIntoWideChar:
5768 SetFailed(FK_IncompatWideStringIntoWideChar);
5769 return;
5770 case SIF_PlainStringIntoUTF8Char:
5771 SetFailed(FK_PlainStringIntoUTF8Char);
5772 return;
5773 case SIF_UTF8StringIntoPlainChar:
5774 SetFailed(FK_UTF8StringIntoPlainChar);
5775 return;
5776 case SIF_Other:
5777 break;
5778 }
5779 }
5780
5781 // Some kinds of initialization permit an array to be initialized from
5782 // another array of the same type, and perform elementwise initialization.
5783 if (Initializer && isa<ConstantArrayType>(DestAT) &&
5784 S.Context.hasSameUnqualifiedType(Initializer->getType(),
5785 Entity.getType()) &&
5786 canPerformArrayCopy(Entity)) {
5787 // If source is a prvalue, use it directly.
5788 if (Initializer->getValueKind() == VK_RValue) {
5789 AddArrayInitStep(DestType, /*IsGNUExtension*/false);
5790 return;
5791 }
5792
5793 // Emit element-at-a-time copy loop.
5794 InitializedEntity Element =
5795 InitializedEntity::InitializeElement(S.Context, 0, Entity);
5796 QualType InitEltT =
5797 Context.getAsArrayType(Initializer->getType())->getElementType();
5798 OpaqueValueExpr OVE(Initializer->getExprLoc(), InitEltT,
5799 Initializer->getValueKind(),
5800 Initializer->getObjectKind());
5801 Expr *OVEAsExpr = &OVE;
5802 InitializeFrom(S, Element, Kind, OVEAsExpr, TopLevelOfInitList,
5803 TreatUnavailableAsInvalid);
5804 if (!Failed())
5805 AddArrayInitLoopStep(Entity.getType(), InitEltT);
5806 return;
5807 }
5808
5809 // Note: as an GNU C extension, we allow initialization of an
5810 // array from a compound literal that creates an array of the same
5811 // type, so long as the initializer has no side effects.
5812 if (!S.getLangOpts().CPlusPlus && Initializer &&
5813 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) &&
5814 Initializer->getType()->isArrayType()) {
5815 const ArrayType *SourceAT
5816 = Context.getAsArrayType(Initializer->getType());
5817 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT))
5818 SetFailed(FK_ArrayTypeMismatch);
5819 else if (Initializer->HasSideEffects(S.Context))
5820 SetFailed(FK_NonConstantArrayInit);
5821 else {
5822 AddArrayInitStep(DestType, /*IsGNUExtension*/true);
5823 }
5824 }
5825 // Note: as a GNU C++ extension, we allow list-initialization of a
5826 // class member of array type from a parenthesized initializer list.
5827 else if (S.getLangOpts().CPlusPlus &&
5828 Entity.getKind() == InitializedEntity::EK_Member &&
5829 Initializer && isa<InitListExpr>(Initializer)) {
5830 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer),
5831 *this, TreatUnavailableAsInvalid);
5832 AddParenthesizedArrayInitStep(DestType);
5833 } else if (DestAT->getElementType()->isCharType())
5834 SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
5835 else if (IsWideCharCompatible(DestAT->getElementType(), Context))
5836 SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral);
5837 else
5838 SetFailed(FK_ArrayNeedsInitList);
5839
5840 return;
5841 }
5842
5843 // Determine whether we should consider writeback conversions for
5844 // Objective-C ARC.
5845 bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
5846 Entity.isParameterKind();
5847
5848 if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
5849 return;
5850
5851 // We're at the end of the line for C: it's either a write-back conversion
5852 // or it's a C assignment. There's no need to check anything else.
5853 if (!S.getLangOpts().CPlusPlus) {
5854 // If allowed, check whether this is an Objective-C writeback conversion.
5855 if (allowObjCWritebackConversion &&
5856 tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
5857 return;
5858 }
5859
5860 if (TryOCLZeroOpaqueTypeInitialization(S, *this, DestType, Initializer))
5861 return;
5862
5863 // Handle initialization in C
5864 AddCAssignmentStep(DestType);
5865 MaybeProduceObjCObject(S, *this, Entity);
5866 return;
5867 }
5868
5869 assert(S.getLangOpts().CPlusPlus);
5870
5871 // - If the destination type is a (possibly cv-qualified) class type:
5872 if (DestType->isRecordType()) {
5873 // - If the initialization is direct-initialization, or if it is
5874 // copy-initialization where the cv-unqualified version of the
5875 // source type is the same class as, or a derived class of, the
5876 // class of the destination, constructors are considered. [...]
5877 if (Kind.getKind() == InitializationKind::IK_Direct ||
5878 (Kind.getKind() == InitializationKind::IK_Copy &&
5879 (Context.hasSameUnqualifiedType(SourceType, DestType) ||
5880 S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType, DestType))))
5881 TryConstructorInitialization(S, Entity, Kind, Args,
5882 DestType, DestType, *this);
5883 // - Otherwise (i.e., for the remaining copy-initialization cases),
5884 // user-defined conversion sequences that can convert from the source
5885 // type to the destination type or (when a conversion function is
5886 // used) to a derived class thereof are enumerated as described in
5887 // 13.3.1.4, and the best one is chosen through overload resolution
5888 // (13.3).
5889 else
5890 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5891 TopLevelOfInitList);
5892 return;
5893 }
5894
5895 assert(Args.size() >= 1 && "Zero-argument case handled above");
5896
5897 // The remaining cases all need a source type.
5898 if (Args.size() > 1) {
5899 SetFailed(FK_TooManyInitsForScalar);
5900 return;
5901 } else if (isa<InitListExpr>(Args[0])) {
5902 SetFailed(FK_ParenthesizedListInitForScalar);
5903 return;
5904 }
5905
5906 // - Otherwise, if the source type is a (possibly cv-qualified) class
5907 // type, conversion functions are considered.
5908 if (!SourceType.isNull() && SourceType->isRecordType()) {
5909 // For a conversion to _Atomic(T) from either T or a class type derived
5910 // from T, initialize the T object then convert to _Atomic type.
5911 bool NeedAtomicConversion = false;
5912 if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) {
5913 if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) ||
5914 S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType,
5915 Atomic->getValueType())) {
5916 DestType = Atomic->getValueType();
5917 NeedAtomicConversion = true;
5918 }
5919 }
5920
5921 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5922 TopLevelOfInitList);
5923 MaybeProduceObjCObject(S, *this, Entity);
5924 if (!Failed() && NeedAtomicConversion)
5925 AddAtomicConversionStep(Entity.getType());
5926 return;
5927 }
5928
5929 // - Otherwise, if the initialization is direct-initialization, the source
5930 // type is std::nullptr_t, and the destination type is bool, the initial
5931 // value of the object being initialized is false.
5932 if (!SourceType.isNull() && SourceType->isNullPtrType() &&
5933 DestType->isBooleanType() &&
5934 Kind.getKind() == InitializationKind::IK_Direct) {
5935 AddConversionSequenceStep(
5936 ImplicitConversionSequence::getNullptrToBool(SourceType, DestType,
5937 Initializer->isGLValue()),
5938 DestType);
5939 return;
5940 }
5941
5942 // - Otherwise, the initial value of the object being initialized is the
5943 // (possibly converted) value of the initializer expression. Standard
5944 // conversions (Clause 4) will be used, if necessary, to convert the
5945 // initializer expression to the cv-unqualified version of the
5946 // destination type; no user-defined conversions are considered.
5947
5948 ImplicitConversionSequence ICS
5949 = S.TryImplicitConversion(Initializer, DestType,
5950 /*SuppressUserConversions*/true,
5951 Sema::AllowedExplicit::None,
5952 /*InOverloadResolution*/ false,
5953 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
5954 allowObjCWritebackConversion);
5955
5956 if (ICS.isStandard() &&
5957 ICS.Standard.Second == ICK_Writeback_Conversion) {
5958 // Objective-C ARC writeback conversion.
5959
5960 // We should copy unless we're passing to an argument explicitly
5961 // marked 'out'.
5962 bool ShouldCopy = true;
5963 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
5964 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
5965
5966 // If there was an lvalue adjustment, add it as a separate conversion.
5967 if (ICS.Standard.First == ICK_Array_To_Pointer ||
5968 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
5969 ImplicitConversionSequence LvalueICS;
5970 LvalueICS.setStandard();
5971 LvalueICS.Standard.setAsIdentityConversion();
5972 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0));
5973 LvalueICS.Standard.First = ICS.Standard.First;
5974 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0));
5975 }
5976
5977 AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy);
5978 } else if (ICS.isBad()) {
5979 DeclAccessPair dap;
5980 if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
5981 AddZeroInitializationStep(Entity.getType());
5982 } else if (Initializer->getType() == Context.OverloadTy &&
5983 !S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
5984 false, dap))
5985 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
5986 else if (Initializer->getType()->isFunctionType() &&
5987 isExprAnUnaddressableFunction(S, Initializer))
5988 SetFailed(InitializationSequence::FK_AddressOfUnaddressableFunction);
5989 else
5990 SetFailed(InitializationSequence::FK_ConversionFailed);
5991 } else {
5992 AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
5993
5994 MaybeProduceObjCObject(S, *this, Entity);
5995 }
5996}
5997
5998InitializationSequence::~InitializationSequence() {
5999 for (auto &S : Steps)
6000 S.Destroy();
6001}
6002
6003//===----------------------------------------------------------------------===//
6004// Perform initialization
6005//===----------------------------------------------------------------------===//
6006static Sema::AssignmentAction
6007getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
6008 switch(Entity.getKind()) {
6009 case InitializedEntity::EK_Variable:
6010 case InitializedEntity::EK_New:
6011 case InitializedEntity::EK_Exception:
6012 case InitializedEntity::EK_Base:
6013 case InitializedEntity::EK_Delegating:
6014 return Sema::AA_Initializing;
6015
6016 case InitializedEntity::EK_Parameter:
6017 if (Entity.getDecl() &&
6018 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
6019 return Sema::AA_Sending;
6020
6021 return Sema::AA_Passing;
6022
6023 case InitializedEntity::EK_Parameter_CF_Audited:
6024 if (Entity.getDecl() &&
6025 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
6026 return Sema::AA_Sending;
6027
6028 return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;
6029
6030 case InitializedEntity::EK_Result:
6031 case InitializedEntity::EK_StmtExprResult: // FIXME: Not quite right.
6032 return Sema::AA_Returning;
6033
6034 case InitializedEntity::EK_Temporary:
6035 case InitializedEntity::EK_RelatedResult:
6036 // FIXME: Can we tell apart casting vs. converting?
6037 return Sema::AA_Casting;
6038
6039 case InitializedEntity::EK_TemplateParameter:
6040 // This is really initialization, but refer to it as conversion for
6041 // consistency with CheckConvertedConstantExpression.
6042 return Sema::AA_Converting;
6043
6044 case InitializedEntity::EK_Member:
6045 case InitializedEntity::EK_Binding:
6046 case InitializedEntity::EK_ArrayElement:
6047 case InitializedEntity::EK_VectorElement:
6048 case InitializedEntity::EK_ComplexElement:
6049 case InitializedEntity::EK_BlockElement:
6050 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6051 case InitializedEntity::EK_LambdaCapture:
6052 case InitializedEntity::EK_CompoundLiteralInit:
6053 return Sema::AA_Initializing;
6054 }
6055
6056 llvm_unreachable("Invalid EntityKind!");
6057}
6058
6059/// Whether we should bind a created object as a temporary when
6060/// initializing the given entity.
6061static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
6062 switch (Entity.getKind()) {
6063 case InitializedEntity::EK_ArrayElement:
6064 case InitializedEntity::EK_Member:
6065 case InitializedEntity::EK_Result:
6066 case InitializedEntity::EK_StmtExprResult:
6067 case InitializedEntity::EK_New:
6068 case InitializedEntity::EK_Variable:
6069 case InitializedEntity::EK_Base:
6070 case InitializedEntity::EK_Delegating:
6071 case InitializedEntity::EK_VectorElement:
6072 case InitializedEntity::EK_ComplexElement:
6073 case InitializedEntity::EK_Exception:
6074 case InitializedEntity::EK_BlockElement:
6075 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6076 case InitializedEntity::EK_LambdaCapture:
6077 case InitializedEntity::EK_CompoundLiteralInit:
6078 case InitializedEntity::EK_TemplateParameter:
6079 return false;
6080
6081 case InitializedEntity::EK_Parameter:
6082 case InitializedEntity::EK_Parameter_CF_Audited:
6083 case InitializedEntity::EK_Temporary:
6084 case InitializedEntity::EK_RelatedResult:
6085 case InitializedEntity::EK_Binding:
6086 return true;
6087 }
6088
6089 llvm_unreachable("missed an InitializedEntity kind?");
6090}
6091
6092/// Whether the given entity, when initialized with an object
6093/// created for that initialization, requires destruction.
6094static bool shouldDestroyEntity(const InitializedEntity &Entity) {
6095 switch (Entity.getKind()) {
6096 case InitializedEntity::EK_Result:
6097 case InitializedEntity::EK_StmtExprResult:
6098 case InitializedEntity::EK_New:
6099 case InitializedEntity::EK_Base:
6100 case InitializedEntity::EK_Delegating:
6101 case InitializedEntity::EK_VectorElement:
6102 case InitializedEntity::EK_ComplexElement:
6103 case InitializedEntity::EK_BlockElement:
6104 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6105 case InitializedEntity::EK_LambdaCapture:
6106 return false;
6107
6108 case InitializedEntity::EK_Member:
6109 case InitializedEntity::EK_Binding:
6110 case InitializedEntity::EK_Variable:
6111 case InitializedEntity::EK_Parameter:
6112 case InitializedEntity::EK_Parameter_CF_Audited:
6113 case InitializedEntity::EK_TemplateParameter:
6114 case InitializedEntity::EK_Temporary:
6115 case InitializedEntity::EK_ArrayElement:
6116 case InitializedEntity::EK_Exception:
6117 case InitializedEntity::EK_CompoundLiteralInit:
6118 case InitializedEntity::EK_RelatedResult:
6119 return true;
6120 }
6121
6122 llvm_unreachable("missed an InitializedEntity kind?");
6123}
6124
6125/// Get the location at which initialization diagnostics should appear.
6126static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
6127 Expr *Initializer) {
6128 switch (Entity.getKind()) {
6129 case InitializedEntity::EK_Result:
6130 case InitializedEntity::EK_StmtExprResult:
6131 return Entity.getReturnLoc();
6132
6133 case InitializedEntity::EK_Exception:
6134 return Entity.getThrowLoc();
6135
6136 case InitializedEntity::EK_Variable:
6137 case InitializedEntity::EK_Binding:
6138 return Entity.getDecl()->getLocation();
6139
6140 case InitializedEntity::EK_LambdaCapture:
6141 return Entity.getCaptureLoc();
6142
6143 case InitializedEntity::EK_ArrayElement:
6144 case InitializedEntity::EK_Member:
6145 case InitializedEntity::EK_Parameter:
6146 case InitializedEntity::EK_Parameter_CF_Audited:
6147 case InitializedEntity::EK_TemplateParameter:
6148 case InitializedEntity::EK_Temporary:
6149 case InitializedEntity::EK_New:
6150 case InitializedEntity::EK_Base:
6151 case InitializedEntity::EK_Delegating:
6152 case InitializedEntity::EK_VectorElement:
6153 case InitializedEntity::EK_ComplexElement:
6154 case InitializedEntity::EK_BlockElement:
6155 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6156 case InitializedEntity::EK_CompoundLiteralInit:
6157 case InitializedEntity::EK_RelatedResult:
6158 return Initializer->getBeginLoc();
6159 }
6160 llvm_unreachable("missed an InitializedEntity kind?");
6161}
6162
6163/// Make a (potentially elidable) temporary copy of the object
6164/// provided by the given initializer by calling the appropriate copy
6165/// constructor.
6166///
6167/// \param S The Sema object used for type-checking.
6168///
6169/// \param T The type of the temporary object, which must either be
6170/// the type of the initializer expression or a superclass thereof.
6171///
6172/// \param Entity The entity being initialized.
6173///
6174/// \param CurInit The initializer expression.
6175///
6176/// \param IsExtraneousCopy Whether this is an "extraneous" copy that
6177/// is permitted in C++03 (but not C++0x) when binding a reference to
6178/// an rvalue.
6179///
6180/// \returns An expression that copies the initializer expression into
6181/// a temporary object, or an error expression if a copy could not be
6182/// created.
6183static ExprResult CopyObject(Sema &S,
6184 QualType T,
6185 const InitializedEntity &Entity,
6186 ExprResult CurInit,
6187 bool IsExtraneousCopy) {
6188 if (CurInit.isInvalid())
6189 return CurInit;
6190 // Determine which class type we're copying to.
6191 Expr *CurInitExpr = (Expr *)CurInit.get();
6192 CXXRecordDecl *Class = nullptr;
6193 if (const RecordType *Record = T->getAs<RecordType>())
6194 Class = cast<CXXRecordDecl>(Record->getDecl());
6195 if (!Class)
6196 return CurInit;
6197
6198 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get());
6199
6200 // Make sure that the type we are copying is complete.
6201 if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete))
6202 return CurInit;
6203
6204 // Perform overload resolution using the class's constructors. Per
6205 // C++11 [dcl.init]p16, second bullet for class types, this initialization
6206 // is direct-initialization.
6207 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6208 DeclContext::lookup_result Ctors = S.LookupConstructors(Class);
6209
6210 OverloadCandidateSet::iterator Best;
6211 switch (ResolveConstructorOverload(
6212 S, Loc, CurInitExpr, CandidateSet, T, Ctors, Best,
6213 /*CopyInitializing=*/false, /*AllowExplicit=*/true,
6214 /*OnlyListConstructors=*/false, /*IsListInit=*/false,
6215 /*SecondStepOfCopyInit=*/true)) {
6216 case OR_Success:
6217 break;
6218
6219 case OR_No_Viable_Function:
6220 CandidateSet.NoteCandidates(
6221 PartialDiagnosticAt(
6222 Loc, S.PDiag(IsExtraneousCopy && !S.isSFINAEContext()
6223 ? diag::ext_rvalue_to_reference_temp_copy_no_viable
6224 : diag::err_temp_copy_no_viable)
6225 << (int)Entity.getKind() << CurInitExpr->getType()
6226 << CurInitExpr->getSourceRange()),
6227 S, OCD_AllCandidates, CurInitExpr);
6228 if (!IsExtraneousCopy || S.isSFINAEContext())
6229 return ExprError();
6230 return CurInit;
6231
6232 case OR_Ambiguous:
6233 CandidateSet.NoteCandidates(
6234 PartialDiagnosticAt(Loc, S.PDiag(diag::err_temp_copy_ambiguous)
6235 << (int)Entity.getKind()
6236 << CurInitExpr->getType()
6237 << CurInitExpr->getSourceRange()),
6238 S, OCD_AmbiguousCandidates, CurInitExpr);
6239 return ExprError();
6240
6241 case OR_Deleted:
6242 S.Diag(Loc, diag::err_temp_copy_deleted)
6243 << (int)Entity.getKind() << CurInitExpr->getType()
6244 << CurInitExpr->getSourceRange();
6245 S.NoteDeletedFunction(Best->Function);
6246 return ExprError();
6247 }
6248
6249 bool HadMultipleCandidates = CandidateSet.size() > 1;
6250
6251 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
6252 SmallVector<Expr*, 8> ConstructorArgs;
6253 CurInit.get(); // Ownership transferred into MultiExprArg, below.
6254
6255 S.CheckConstructorAccess(Loc, Constructor, Best->FoundDecl, Entity,
6256 IsExtraneousCopy);
6257
6258 if (IsExtraneousCopy) {
6259 // If this is a totally extraneous copy for C++03 reference
6260 // binding purposes, just return the original initialization
6261 // expression. We don't generate an (elided) copy operation here
6262 // because doing so would require us to pass down a flag to avoid
6263 // infinite recursion, where each step adds another extraneous,
6264 // elidable copy.
6265
6266 // Instantiate the default arguments of any extra parameters in
6267 // the selected copy constructor, as if we were going to create a
6268 // proper call to the copy constructor.
6269 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) {
6270 ParmVarDecl *Parm = Constructor->getParamDecl(I);
6271 if (S.RequireCompleteType(Loc, Parm->getType(),
6272 diag::err_call_incomplete_argument))
6273 break;
6274
6275 // Build the default argument expression; we don't actually care
6276 // if this succeeds or not, because this routine will complain
6277 // if there was a problem.
6278 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm);
6279 }
6280
6281 return CurInitExpr;
6282 }
6283
6284 // Determine the arguments required to actually perform the
6285 // constructor call (we might have derived-to-base conversions, or
6286 // the copy constructor may have default arguments).
6287 if (S.CompleteConstructorCall(Constructor, CurInitExpr, Loc, ConstructorArgs))
6288 return ExprError();
6289
6290 // C++0x [class.copy]p32:
6291 // When certain criteria are met, an implementation is allowed to
6292 // omit the copy/move construction of a class object, even if the
6293 // copy/move constructor and/or destructor for the object have
6294 // side effects. [...]
6295 // - when a temporary class object that has not been bound to a
6296 // reference (12.2) would be copied/moved to a class object
6297 // with the same cv-unqualified type, the copy/move operation
6298 // can be omitted by constructing the temporary object
6299 // directly into the target of the omitted copy/move
6300 //
6301 // Note that the other three bullets are handled elsewhere. Copy
6302 // elision for return statements and throw expressions are handled as part
6303 // of constructor initialization, while copy elision for exception handlers
6304 // is handled by the run-time.
6305 //
6306 // FIXME: If the function parameter is not the same type as the temporary, we
6307 // should still be able to elide the copy, but we don't have a way to
6308 // represent in the AST how much should be elided in this case.
6309 bool Elidable =
6310 CurInitExpr->isTemporaryObject(S.Context, Class) &&
6311 S.Context.hasSameUnqualifiedType(
6312 Best->Function->getParamDecl(0)->getType().getNonReferenceType(),
6313 CurInitExpr->getType());
6314
6315 // Actually perform the constructor call.
6316 CurInit = S.BuildCXXConstructExpr(Loc, T, Best->FoundDecl, Constructor,
6317 Elidable,
6318 ConstructorArgs,
6319 HadMultipleCandidates,
6320 /*ListInit*/ false,
6321 /*StdInitListInit*/ false,
6322 /*ZeroInit*/ false,
6323 CXXConstructExpr::CK_Complete,
6324 SourceRange());
6325
6326 // If we're supposed to bind temporaries, do so.
6327 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity))
6328 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
6329 return CurInit;
6330}
6331
6332/// Check whether elidable copy construction for binding a reference to
6333/// a temporary would have succeeded if we were building in C++98 mode, for
6334/// -Wc++98-compat.
6335static void CheckCXX98CompatAccessibleCopy(Sema &S,
6336 const InitializedEntity &Entity,
6337 Expr *CurInitExpr) {
6338 assert(S.getLangOpts().CPlusPlus11);
6339
6340 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>();
6341 if (!Record)
6342 return;
6343
6344 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr);
6345 if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc))
6346 return;
6347
6348 // Find constructors which would have been considered.
6349 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
6350 DeclContext::lookup_result Ctors =
6351 S.LookupConstructors(cast<CXXRecordDecl>(Record->getDecl()));
6352
6353 // Perform overload resolution.
6354 OverloadCandidateSet::iterator Best;
6355 OverloadingResult OR = ResolveConstructorOverload(
6356 S, Loc, CurInitExpr, CandidateSet, CurInitExpr->getType(), Ctors, Best,
6357 /*CopyInitializing=*/false, /*AllowExplicit=*/true,
6358 /*OnlyListConstructors=*/false, /*IsListInit=*/false,
6359 /*SecondStepOfCopyInit=*/true);
6360
6361 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy)
6362 << OR << (int)Entity.getKind() << CurInitExpr->getType()
6363 << CurInitExpr->getSourceRange();
6364
6365 switch (OR) {
6366 case OR_Success:
6367 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function),
6368 Best->FoundDecl, Entity, Diag);
6369 // FIXME: Check default arguments as far as that's possible.
6370 break;
6371
6372 case OR_No_Viable_Function:
6373 CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
6374 OCD_AllCandidates, CurInitExpr);
6375 break;
6376
6377 case OR_Ambiguous:
6378 CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
6379 OCD_AmbiguousCandidates, CurInitExpr);
6380 break;
6381
6382 case OR_Deleted:
6383 S.Diag(Loc, Diag);
6384 S.NoteDeletedFunction(Best->Function);
6385 break;
6386 }
6387}
6388
6389void InitializationSequence::PrintInitLocationNote(Sema &S,
6390 const InitializedEntity &Entity) {
6391 if (Entity.isParamOrTemplateParamKind() && Entity.getDecl()) {
6392 if (Entity.getDecl()->getLocation().isInvalid())
6393 return;
6394
6395 if (Entity.getDecl()->getDeclName())
6396 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here)
6397 << Entity.getDecl()->getDeclName();
6398 else
6399 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here);
6400 }
6401 else if (Entity.getKind() == InitializedEntity::EK_RelatedResult &&
6402 Entity.getMethodDecl())
6403 S.Diag(Entity.getMethodDecl()->getLocation(),
6404 diag::note_method_return_type_change)
6405 << Entity.getMethodDecl()->getDeclName();
6406}
6407
6408/// Returns true if the parameters describe a constructor initialization of
6409/// an explicit temporary object, e.g. "Point(x, y)".
6410static bool isExplicitTemporary(const InitializedEntity &Entity,
6411 const InitializationKind &Kind,
6412 unsigned NumArgs) {
6413 switch (Entity.getKind()) {
6414 case InitializedEntity::EK_Temporary:
6415 case InitializedEntity::EK_CompoundLiteralInit:
6416 case InitializedEntity::EK_RelatedResult:
6417 break;
6418 default:
6419 return false;
6420 }
6421
6422 switch (Kind.getKind()) {
6423 case InitializationKind::IK_DirectList:
6424 return true;
6425 // FIXME: Hack to work around cast weirdness.
6426 case InitializationKind::IK_Direct:
6427 case InitializationKind::IK_Value:
6428 return NumArgs != 1;
6429 default:
6430 return false;
6431 }
6432}
6433
6434static ExprResult
6435PerformConstructorInitialization(Sema &S,
6436 const InitializedEntity &Entity,
6437 const InitializationKind &Kind,
6438 MultiExprArg Args,
6439 const InitializationSequence::Step& Step,
6440 bool &ConstructorInitRequiresZeroInit,
6441 bool IsListInitialization,
6442 bool IsStdInitListInitialization,
6443 SourceLocation LBraceLoc,
6444 SourceLocation RBraceLoc) {
6445 unsigned NumArgs = Args.size();
6446 CXXConstructorDecl *Constructor
6447 = cast<CXXConstructorDecl>(Step.Function.Function);
6448 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates;
6449
6450 // Build a call to the selected constructor.
6451 SmallVector<Expr*, 8> ConstructorArgs;
6452 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid())
6453 ? Kind.getEqualLoc()
6454 : Kind.getLocation();
6455
6456 if (Kind.getKind() == InitializationKind::IK_Default) {
6457 // Force even a trivial, implicit default constructor to be
6458 // semantically checked. We do this explicitly because we don't build
6459 // the definition for completely trivial constructors.
6460 assert(Constructor->getParent() && "No parent class for constructor.");
6461 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
6462 Constructor->isTrivial() && !Constructor->isUsed(false)) {
6463 S.runWithSufficientStackSpace(Loc, [&] {
6464 S.DefineImplicitDefaultConstructor(Loc, Constructor);
6465 });
6466 }
6467 }
6468
6469 ExprResult CurInit((Expr *)nullptr);
6470
6471 // C++ [over.match.copy]p1:
6472 // - When initializing a temporary to be bound to the first parameter
6473 // of a constructor that takes a reference to possibly cv-qualified
6474 // T as its first argument, called with a single argument in the
6475 // context of direct-initialization, explicit conversion functions
6476 // are also considered.
6477 bool AllowExplicitConv =
6478 Kind.AllowExplicit() && !Kind.isCopyInit() && Args.size() == 1 &&
6479 hasCopyOrMoveCtorParam(S.Context,
6480 getConstructorInfo(Step.Function.FoundDecl));
6481
6482 // Determine the arguments required to actually perform the constructor
6483 // call.
6484 if (S.CompleteConstructorCall(Constructor, Args,
6485 Loc, ConstructorArgs,
6486 AllowExplicitConv,
6487 IsListInitialization))
6488 return ExprError();
6489
6490
6491 if (isExplicitTemporary(Entity, Kind, NumArgs)) {
6492 // An explicitly-constructed temporary, e.g., X(1, 2).
6493 if (S.DiagnoseUseOfDecl(Constructor, Loc))
6494 return ExprError();
6495
6496 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
6497 if (!TSInfo)
6498 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc);
6499 SourceRange ParenOrBraceRange =
6500 (Kind.getKind() == InitializationKind::IK_DirectList)
6501 ? SourceRange(LBraceLoc, RBraceLoc)
6502 : Kind.getParenOrBraceRange();
6503
6504 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(
6505 Step.Function.FoundDecl.getDecl())) {
6506 Constructor = S.findInheritingConstructor(Loc, Constructor, Shadow);
6507 if (S.DiagnoseUseOfDecl(Constructor, Loc))
6508 return ExprError();
6509 }
6510 S.MarkFunctionReferenced(Loc, Constructor);
6511
6512 CurInit = S.CheckForImmediateInvocation(
6513 CXXTemporaryObjectExpr::Create(
6514 S.Context, Constructor,
6515 Entity.getType().getNonLValueExprType(S.Context), TSInfo,
6516 ConstructorArgs, ParenOrBraceRange, HadMultipleCandidates,
6517 IsListInitialization, IsStdInitListInitialization,
6518 ConstructorInitRequiresZeroInit),
6519 Constructor);
6520 } else {
6521 CXXConstructExpr::ConstructionKind ConstructKind =
6522 CXXConstructExpr::CK_Complete;
6523
6524 if (Entity.getKind() == InitializedEntity::EK_Base) {
6525 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ?
6526 CXXConstructExpr::CK_VirtualBase :
6527 CXXConstructExpr::CK_NonVirtualBase;
6528 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) {
6529 ConstructKind = CXXConstructExpr::CK_Delegating;
6530 }
6531
6532 // Only get the parenthesis or brace range if it is a list initialization or
6533 // direct construction.
6534 SourceRange ParenOrBraceRange;
6535 if (IsListInitialization)
6536 ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc);
6537 else if (Kind.getKind() == InitializationKind::IK_Direct)
6538 ParenOrBraceRange = Kind.getParenOrBraceRange();
6539
6540 // If the entity allows NRVO, mark the construction as elidable
6541 // unconditionally.
6542 if (Entity.allowsNRVO())
6543 CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
6544 Step.Function.FoundDecl,
6545 Constructor, /*Elidable=*/true,
6546 ConstructorArgs,
6547 HadMultipleCandidates,
6548 IsListInitialization,
6549 IsStdInitListInitialization,
6550 ConstructorInitRequiresZeroInit,
6551 ConstructKind,
6552 ParenOrBraceRange);
6553 else
6554 CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
6555 Step.Function.FoundDecl,
6556 Constructor,
6557 ConstructorArgs,
6558 HadMultipleCandidates,
6559 IsListInitialization,
6560 IsStdInitListInitialization,
6561 ConstructorInitRequiresZeroInit,
6562 ConstructKind,
6563 ParenOrBraceRange);
6564 }
6565 if (CurInit.isInvalid())
6566 return ExprError();
6567
6568 // Only check access if all of that succeeded.
6569 S.CheckConstructorAccess(Loc, Constructor, Step.Function.FoundDecl, Entity);
6570 if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc))
6571 return ExprError();
6572
6573 if (const ArrayType *AT = S.Context.getAsArrayType(Entity.getType()))
6574 if (checkDestructorReference(S.Context.getBaseElementType(AT), Loc, S))
6575 return ExprError();
6576
6577 if (shouldBindAsTemporary(Entity))
6578 CurInit = S.MaybeBindToTemporary(CurInit.get());
6579
6580 return CurInit;
6581}
6582
6583namespace {
6584enum LifetimeKind {
6585 /// The lifetime of a temporary bound to this entity ends at the end of the
6586 /// full-expression, and that's (probably) fine.
6587 LK_FullExpression,
6588
6589 /// The lifetime of a temporary bound to this entity is extended to the
6590 /// lifeitme of the entity itself.
6591 LK_Extended,
6592
6593 /// The lifetime of a temporary bound to this entity probably ends too soon,
6594 /// because the entity is allocated in a new-expression.
6595 LK_New,
6596
6597 /// The lifetime of a temporary bound to this entity ends too soon, because
6598 /// the entity is a return object.
6599 LK_Return,
6600
6601 /// The lifetime of a temporary bound to this entity ends too soon, because
6602 /// the entity is the result of a statement expression.
6603 LK_StmtExprResult,
6604
6605 /// This is a mem-initializer: if it would extend a temporary (other than via
6606 /// a default member initializer), the program is ill-formed.
6607 LK_MemInitializer,
6608};
6609using LifetimeResult =
6610 llvm::PointerIntPair<const InitializedEntity *, 3, LifetimeKind>;
6611}
6612
6613/// Determine the declaration which an initialized entity ultimately refers to,
6614/// for the purpose of lifetime-extending a temporary bound to a reference in
6615/// the initialization of \p Entity.
6616static LifetimeResult getEntityLifetime(
6617 const InitializedEntity *Entity,
6618 const InitializedEntity *InitField = nullptr) {
6619 // C++11 [class.temporary]p5:
6620 switch (Entity->getKind()) {
6621 case InitializedEntity::EK_Variable:
6622 // The temporary [...] persists for the lifetime of the reference
6623 return {Entity, LK_Extended};
6624
6625 case InitializedEntity::EK_Member:
6626 // For subobjects, we look at the complete object.
6627 if (Entity->getParent())
6628 return getEntityLifetime(Entity->getParent(), Entity);
6629
6630 // except:
6631 // C++17 [class.base.init]p8:
6632 // A temporary expression bound to a reference member in a
6633 // mem-initializer is ill-formed.
6634 // C++17 [class.base.init]p11:
6635 // A temporary expression bound to a reference member from a
6636 // default member initializer is ill-formed.
6637 //
6638 // The context of p11 and its example suggest that it's only the use of a
6639 // default member initializer from a constructor that makes the program
6640 // ill-formed, not its mere existence, and that it can even be used by
6641 // aggregate initialization.
6642 return {Entity, Entity->isDefaultMemberInitializer() ? LK_Extended
6643 : LK_MemInitializer};
6644
6645 case InitializedEntity::EK_Binding:
6646 // Per [dcl.decomp]p3, the binding is treated as a variable of reference
6647 // type.
6648 return {Entity, LK_Extended};
6649
6650 case InitializedEntity::EK_Parameter:
6651 case InitializedEntity::EK_Parameter_CF_Audited:
6652 // -- A temporary bound to a reference parameter in a function call
6653 // persists until the completion of the full-expression containing
6654 // the call.
6655 return {nullptr, LK_FullExpression};
6656
6657 case InitializedEntity::EK_TemplateParameter:
6658 // FIXME: This will always be ill-formed; should we eagerly diagnose it here?
6659 return {nullptr, LK_FullExpression};
6660
6661 case InitializedEntity::EK_Result:
6662 // -- The lifetime of a temporary bound to the returned value in a
6663 // function return statement is not extended; the temporary is
6664 // destroyed at the end of the full-expression in the return statement.
6665 return {nullptr, LK_Return};
6666
6667 case InitializedEntity::EK_StmtExprResult:
6668 // FIXME: Should we lifetime-extend through the result of a statement
6669 // expression?
6670 return {nullptr, LK_StmtExprResult};
6671
6672 case InitializedEntity::EK_New:
6673 // -- A temporary bound to a reference in a new-initializer persists
6674 // until the completion of the full-expression containing the
6675 // new-initializer.
6676 return {nullptr, LK_New};
6677
6678 case InitializedEntity::EK_Temporary:
6679 case InitializedEntity::EK_CompoundLiteralInit:
6680 case InitializedEntity::EK_RelatedResult:
6681 // We don't yet know the storage duration of the surrounding temporary.
6682 // Assume it's got full-expression duration for now, it will patch up our
6683 // storage duration if that's not correct.
6684 return {nullptr, LK_FullExpression};
6685
6686 case InitializedEntity::EK_ArrayElement:
6687 // For subobjects, we look at the complete object.
6688 return getEntityLifetime(Entity->getParent(), InitField);
6689
6690 case InitializedEntity::EK_Base:
6691 // For subobjects, we look at the complete object.
6692 if (Entity->getParent())
6693 return getEntityLifetime(Entity->getParent(), InitField);
6694 return {InitField, LK_MemInitializer};
6695
6696 case InitializedEntity::EK_Delegating:
6697 // We can reach this case for aggregate initialization in a constructor:
6698 // struct A { int &&r; };
6699 // struct B : A { B() : A{0} {} };
6700 // In this case, use the outermost field decl as the context.
6701 return {InitField, LK_MemInitializer};
6702
6703 case InitializedEntity::EK_BlockElement:
6704 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
6705 case InitializedEntity::EK_LambdaCapture:
6706 case InitializedEntity::EK_VectorElement:
6707 case InitializedEntity::EK_ComplexElement:
6708 return {nullptr, LK_FullExpression};
6709
6710 case InitializedEntity::EK_Exception:
6711 // FIXME: Can we diagnose lifetime problems with exceptions?
6712 return {nullptr, LK_FullExpression};
6713 }
6714 llvm_unreachable("unknown entity kind");
6715}
6716
6717namespace {
6718enum ReferenceKind {
6719 /// Lifetime would be extended by a reference binding to a temporary.
6720 RK_ReferenceBinding,
6721 /// Lifetime would be extended by a std::initializer_list object binding to
6722 /// its backing array.
6723 RK_StdInitializerList,
6724};
6725
6726/// A temporary or local variable. This will be one of:
6727/// * A MaterializeTemporaryExpr.
6728/// * A DeclRefExpr whose declaration is a local.
6729/// * An AddrLabelExpr.
6730/// * A BlockExpr for a block with captures.
6731using Local = Expr*;
6732
6733/// Expressions we stepped over when looking for the local state. Any steps
6734/// that would inhibit lifetime extension or take us out of subexpressions of
6735/// the initializer are included.
6736struct IndirectLocalPathEntry {
6737 enum EntryKind {
6738 DefaultInit,
6739 AddressOf,
6740 VarInit,
6741 LValToRVal,
6742 LifetimeBoundCall,
6743 TemporaryCopy,
6744 LambdaCaptureInit,
6745 GslReferenceInit,
6746 GslPointerInit
6747 } Kind;
6748 Expr *E;
6749 union {
6750 const Decl *D = nullptr;
6751 const LambdaCapture *Capture;
6752 };
6753 IndirectLocalPathEntry() {}
6754 IndirectLocalPathEntry(EntryKind K, Expr *E) : Kind(K), E(E) {}
6755 IndirectLocalPathEntry(EntryKind K, Expr *E, const Decl *D)
6756 : Kind(K), E(E), D(D) {}
6757 IndirectLocalPathEntry(EntryKind K, Expr *E, const LambdaCapture *Capture)
6758 : Kind(K), E(E), Capture(Capture) {}
6759};
6760
6761using IndirectLocalPath = llvm::SmallVectorImpl<IndirectLocalPathEntry>;
6762
6763struct RevertToOldSizeRAII {
6764 IndirectLocalPath &Path;
6765 unsigned OldSize = Path.size();
6766 RevertToOldSizeRAII(IndirectLocalPath &Path) : Path(Path) {}
6767 ~RevertToOldSizeRAII() { Path.resize(OldSize); }
6768};
6769
6770using LocalVisitor = llvm::function_ref<bool(IndirectLocalPath &Path, Local L,
6771 ReferenceKind RK)>;
6772}
6773
6774static bool isVarOnPath(IndirectLocalPath &Path, VarDecl *VD) {
6775 for (auto E : Path)
6776 if (E.Kind == IndirectLocalPathEntry::VarInit && E.D == VD)
6777 return true;
6778 return false;
6779}
6780
6781static bool pathContainsInit(IndirectLocalPath &Path) {
6782 return llvm::any_of(Path, [=](IndirectLocalPathEntry E) {
6783 return E.Kind == IndirectLocalPathEntry::DefaultInit ||
6784 E.Kind == IndirectLocalPathEntry::VarInit;
6785 });
6786}
6787
6788static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
6789 Expr *Init, LocalVisitor Visit,
6790 bool RevisitSubinits,
6791 bool EnableLifetimeWarnings);
6792
6793static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
6794 Expr *Init, ReferenceKind RK,
6795 LocalVisitor Visit,
6796 bool EnableLifetimeWarnings);
6797
6798template <typename T> static bool isRecordWithAttr(QualType Type) {
6799 if (auto *RD = Type->getAsCXXRecordDecl())
6800 return RD->hasAttr<T>();
6801 return false;
6802}
6803
6804// Decl::isInStdNamespace will return false for iterators in some STL
6805// implementations due to them being defined in a namespace outside of the std
6806// namespace.
6807static bool isInStlNamespace(const Decl *D) {
6808 const DeclContext *DC = D->getDeclContext();
6809 if (!DC)
6810 return false;
6811 if (const auto *ND = dyn_cast<NamespaceDecl>(DC))
6812 if (const IdentifierInfo *II = ND->getIdentifier()) {
6813 StringRef Name = II->getName();
6814 if (Name.size() >= 2 && Name.front() == '_' &&
6815 (Name[1] == '_' || isUppercase(Name[1])))
6816 return true;
6817 }
6818
6819 return DC->isStdNamespace();
6820}
6821
6822static bool shouldTrackImplicitObjectArg(const CXXMethodDecl *Callee) {
6823 if (auto *Conv = dyn_cast_or_null<CXXConversionDecl>(Callee))
6824 if (isRecordWithAttr<PointerAttr>(Conv->getConversionType()))
6825 return true;
6826 if (!isInStlNamespace(Callee->getParent()))
6827 return false;
6828 if (!isRecordWithAttr<PointerAttr>(Callee->getThisObjectType()) &&
6829 !isRecordWithAttr<OwnerAttr>(Callee->getThisObjectType()))
6830 return false;
6831 if (Callee->getReturnType()->isPointerType() ||
6832 isRecordWithAttr<PointerAttr>(Callee->getReturnType())) {
6833 if (!Callee->getIdentifier())
6834 return false;
6835 return llvm::StringSwitch<bool>(Callee->getName())
6836 .Cases("begin", "rbegin", "cbegin", "crbegin", true)
6837 .Cases("end", "rend", "cend", "crend", true)
6838 .Cases("c_str", "data", "get", true)
6839 // Map and set types.
6840 .Cases("find", "equal_range", "lower_bound", "upper_bound", true)
6841 .Default(false);
6842 } else if (Callee->getReturnType()->isReferenceType()) {
6843 if (!Callee->getIdentifier()) {
6844 auto OO = Callee->getOverloadedOperator();
6845 return OO == OverloadedOperatorKind::OO_Subscript ||
6846 OO == OverloadedOperatorKind::OO_Star;
6847 }
6848 return llvm::StringSwitch<bool>(Callee->getName())
6849 .Cases("front", "back", "at", "top", "value", true)
6850 .Default(false);
6851 }
6852 return false;
6853}
6854
6855static bool shouldTrackFirstArgument(const FunctionDecl *FD) {
6856 if (!FD->getIdentifier() || FD->getNumParams() != 1)
6857 return false;
6858 const auto *RD = FD->getParamDecl(0)->getType()->getPointeeCXXRecordDecl();
6859 if (!FD->isInStdNamespace() || !RD || !RD->isInStdNamespace())
6860 return false;
6861 if (!isRecordWithAttr<PointerAttr>(QualType(RD->getTypeForDecl(), 0)) &&
6862 !isRecordWithAttr<OwnerAttr>(QualType(RD->getTypeForDecl(), 0)))
6863 return false;
6864 if (FD->getReturnType()->isPointerType() ||
6865 isRecordWithAttr<PointerAttr>(FD->getReturnType())) {
6866 return llvm::StringSwitch<bool>(FD->getName())
6867 .Cases("begin", "rbegin", "cbegin", "crbegin", true)
6868 .Cases("end", "rend", "cend", "crend", true)
6869 .Case("data", true)
6870 .Default(false);
6871 } else if (FD->getReturnType()->isReferenceType()) {
6872 return llvm::StringSwitch<bool>(FD->getName())
6873 .Cases("get", "any_cast", true)
6874 .Default(false);
6875 }
6876 return false;
6877}
6878
6879static void handleGslAnnotatedTypes(IndirectLocalPath &Path, Expr *Call,
6880 LocalVisitor Visit) {
6881 auto VisitPointerArg = [&](const Decl *D, Expr *Arg, bool Value) {
6882 // We are not interested in the temporary base objects of gsl Pointers:
6883 // Temp().ptr; // Here ptr might not dangle.
6884 if (isa<MemberExpr>(Arg->IgnoreImpCasts()))
6885 return;
6886 // Once we initialized a value with a reference, it can no longer dangle.
6887 if (!Value) {
6888 for (auto It = Path.rbegin(), End = Path.rend(); It != End; ++It) {
6889 if (It->Kind == IndirectLocalPathEntry::GslReferenceInit)
6890 continue;
6891 if (It->Kind == IndirectLocalPathEntry::GslPointerInit)
6892 return;
6893 break;
6894 }
6895 }
6896 Path.push_back({Value ? IndirectLocalPathEntry::GslPointerInit
6897 : IndirectLocalPathEntry::GslReferenceInit,
6898 Arg, D});
6899 if (Arg->isGLValue())
6900 visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
6901 Visit,
6902 /*EnableLifetimeWarnings=*/true);
6903 else
6904 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
6905 /*EnableLifetimeWarnings=*/true);
6906 Path.pop_back();
6907 };
6908
6909 if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
6910 const auto *MD = cast_or_null<CXXMethodDecl>(MCE->getDirectCallee());
6911 if (MD && shouldTrackImplicitObjectArg(MD))
6912 VisitPointerArg(MD, MCE->getImplicitObjectArgument(),
6913 !MD->getReturnType()->isReferenceType());
6914 return;
6915 } else if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(Call)) {
6916 FunctionDecl *Callee = OCE->getDirectCallee();
6917 if (Callee && Callee->isCXXInstanceMember() &&
6918 shouldTrackImplicitObjectArg(cast<CXXMethodDecl>(Callee)))
6919 VisitPointerArg(Callee, OCE->getArg(0),
6920 !Callee->getReturnType()->isReferenceType());
6921 return;
6922 } else if (auto *CE = dyn_cast<CallExpr>(Call)) {
6923 FunctionDecl *Callee = CE->getDirectCallee();
6924 if (Callee && shouldTrackFirstArgument(Callee))
6925 VisitPointerArg(Callee, CE->getArg(0),
6926 !Callee->getReturnType()->isReferenceType());
6927 return;
6928 }
6929
6930 if (auto *CCE = dyn_cast<CXXConstructExpr>(Call)) {
6931 const auto *Ctor = CCE->getConstructor();
6932 const CXXRecordDecl *RD = Ctor->getParent();
6933 if (CCE->getNumArgs() > 0 && RD->hasAttr<PointerAttr>())
6934 VisitPointerArg(Ctor->getParamDecl(0), CCE->getArgs()[0], true);
6935 }
6936}
6937
6938static bool implicitObjectParamIsLifetimeBound(const FunctionDecl *FD) {
6939 const TypeSourceInfo *TSI = FD->getTypeSourceInfo();
6940 if (!TSI)
6941 return false;
6942 // Don't declare this variable in the second operand of the for-statement;
6943 // GCC miscompiles that by ending its lifetime before evaluating the
6944 // third operand. See gcc.gnu.org/PR86769.
6945 AttributedTypeLoc ATL;
6946 for (TypeLoc TL = TSI->getTypeLoc();
6947 (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
6948 TL = ATL.getModifiedLoc()) {
6949 if (ATL.getAttrAs<LifetimeBoundAttr>())
6950 return true;
6951 }
6952
6953 // Assume that all assignment operators with a "normal" return type return
6954 // *this, that is, an lvalue reference that is the same type as the implicit
6955 // object parameter (or the LHS for a non-member operator$=).
6956 OverloadedOperatorKind OO = FD->getDeclName().getCXXOverloadedOperator();
6957 if (OO == OO_Equal || isCompoundAssignmentOperator(OO)) {
6958 QualType RetT = FD->getReturnType();
6959 if (RetT->isLValueReferenceType()) {
6960 ASTContext &Ctx = FD->getASTContext();
6961 QualType LHST;
6962 auto *MD = dyn_cast<CXXMethodDecl>(FD);
6963 if (MD && MD->isCXXInstanceMember())
6964 LHST = Ctx.getLValueReferenceType(MD->getThisObjectType());
6965 else
6966 LHST = MD->getParamDecl(0)->getType();
6967 if (Ctx.hasSameType(RetT, LHST))
6968 return true;
6969 }
6970 }
6971
6972 return false;
6973}
6974
6975static void visitLifetimeBoundArguments(IndirectLocalPath &Path, Expr *Call,
6976 LocalVisitor Visit) {
6977 const FunctionDecl *Callee;
6978 ArrayRef<Expr*> Args;
6979
6980 if (auto *CE = dyn_cast<CallExpr>(Call)) {
6981 Callee = CE->getDirectCallee();
6982 Args = llvm::makeArrayRef(CE->getArgs(), CE->getNumArgs());
6983 } else {
6984 auto *CCE = cast<CXXConstructExpr>(Call);
6985 Callee = CCE->getConstructor();
6986 Args = llvm::makeArrayRef(CCE->getArgs(), CCE->getNumArgs());
6987 }
6988 if (!Callee)
6989 return;
6990
6991 Expr *ObjectArg = nullptr;
6992 if (isa<CXXOperatorCallExpr>(Call) && Callee->isCXXInstanceMember()) {
6993 ObjectArg = Args[0];
6994 Args = Args.slice(1);
6995 } else if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
6996 ObjectArg = MCE->getImplicitObjectArgument();
6997 }
6998
6999 auto VisitLifetimeBoundArg = [&](const Decl *D, Expr *Arg) {
7000 Path.push_back({IndirectLocalPathEntry::LifetimeBoundCall, Arg, D});
7001 if (Arg->isGLValue())
7002 visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
7003 Visit,
7004 /*EnableLifetimeWarnings=*/false);
7005 else
7006 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
7007 /*EnableLifetimeWarnings=*/false);
7008 Path.pop_back();
7009 };
7010
7011 if (ObjectArg && implicitObjectParamIsLifetimeBound(Callee))
7012 VisitLifetimeBoundArg(Callee, ObjectArg);
7013
7014 for (unsigned I = 0,
7015 N = std::min<unsigned>(Callee->getNumParams(), Args.size());
7016 I != N; ++I) {
7017 if (Callee->getParamDecl(I)->hasAttr<LifetimeBoundAttr>())
7018 VisitLifetimeBoundArg(Callee->getParamDecl(I), Args[I]);
7019 }
7020}
7021
7022/// Visit the locals that would be reachable through a reference bound to the
7023/// glvalue expression \c Init.
7024static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
7025 Expr *Init, ReferenceKind RK,
7026 LocalVisitor Visit,
7027 bool EnableLifetimeWarnings) {
7028 RevertToOldSizeRAII RAII(Path);
7029
7030 // Walk past any constructs which we can lifetime-extend across.
7031 Expr *Old;
7032 do {
7033 Old = Init;
7034
7035 if (auto *FE = dyn_cast<FullExpr>(Init))
7036 Init = FE->getSubExpr();
7037
7038 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
7039 // If this is just redundant braces around an initializer, step over it.
7040 if (ILE->isTransparent())
7041 Init = ILE->getInit(0);
7042 }
7043
7044 // Step over any subobject adjustments; we may have a materialized
7045 // temporary inside them.
7046 Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());
7047
7048 // Per current approach for DR1376, look through casts to reference type
7049 // when performing lifetime extension.
7050 if (CastExpr *CE = dyn_cast<CastExpr>(Init))
7051 if (CE->getSubExpr()->isGLValue())
7052 Init = CE->getSubExpr();
7053
7054 // Per the current approach for DR1299, look through array element access
7055 // on array glvalues when performing lifetime extension.
7056 if (auto *ASE = dyn_cast<ArraySubscriptExpr>(Init)) {
7057 Init = ASE->getBase();
7058 auto *ICE = dyn_cast<ImplicitCastExpr>(Init);
7059 if (ICE && ICE->getCastKind() == CK_ArrayToPointerDecay)
7060 Init = ICE->getSubExpr();
7061 else
7062 // We can't lifetime extend through this but we might still find some
7063 // retained temporaries.
7064 return visitLocalsRetainedByInitializer(Path, Init, Visit, true,
7065 EnableLifetimeWarnings);
7066 }
7067
7068 // Step into CXXDefaultInitExprs so we can diagnose cases where a
7069 // constructor inherits one as an implicit mem-initializer.
7070 if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
7071 Path.push_back(
7072 {IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
7073 Init = DIE->getExpr();
7074 }
7075 } while (Init != Old);
7076
7077 if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(Init)) {
7078 if (Visit(Path, Local(MTE), RK))
7079 visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit, true,
7080 EnableLifetimeWarnings);
7081 }
7082
7083 if (isa<CallExpr>(Init)) {
7084 if (EnableLifetimeWarnings)
7085 handleGslAnnotatedTypes(Path, Init, Visit);
7086 return visitLifetimeBoundArguments(Path, Init, Visit);
7087 }
7088
7089 switch (Init->getStmtClass()) {
7090 case Stmt::DeclRefExprClass: {
7091 // If we find the name of a local non-reference parameter, we could have a
7092 // lifetime problem.
7093 auto *DRE = cast<DeclRefExpr>(Init);
7094 auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
7095 if (VD && VD->hasLocalStorage() &&
7096 !DRE->refersToEnclosingVariableOrCapture()) {
7097 if (!VD->getType()->isReferenceType()) {
7098 Visit(Path, Local(DRE), RK);
7099 } else if (isa<ParmVarDecl>(DRE->getDecl())) {
7100 // The lifetime of a reference parameter is unknown; assume it's OK
7101 // for now.
7102 break;
7103 } else if (VD->getInit() && !isVarOnPath(Path, VD)) {
7104 Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
7105 visitLocalsRetainedByReferenceBinding(Path, VD->getInit(),
7106 RK_ReferenceBinding, Visit,
7107 EnableLifetimeWarnings);
7108 }
7109 }
7110 break;
7111 }
7112
7113 case Stmt::UnaryOperatorClass: {
7114 // The only unary operator that make sense to handle here
7115 // is Deref. All others don't resolve to a "name." This includes
7116 // handling all sorts of rvalues passed to a unary operator.
7117 const UnaryOperator *U = cast<UnaryOperator>(Init);
7118 if (U->getOpcode() == UO_Deref)
7119 visitLocalsRetainedByInitializer(Path, U->getSubExpr(), Visit, true,
7120 EnableLifetimeWarnings);
7121 break;
7122 }
7123
7124 case Stmt::OMPArraySectionExprClass: {
7125 visitLocalsRetainedByInitializer(Path,
7126 cast<OMPArraySectionExpr>(Init)->getBase(),
7127 Visit, true, EnableLifetimeWarnings);
7128 break;
7129 }
7130
7131 case Stmt::ConditionalOperatorClass:
7132 case Stmt::BinaryConditionalOperatorClass: {
7133 auto *C = cast<AbstractConditionalOperator>(Init);
7134 if (!C->getTrueExpr()->getType()->isVoidType())
7135 visitLocalsRetainedByReferenceBinding(Path, C->getTrueExpr(), RK, Visit,
7136 EnableLifetimeWarnings);
7137 if (!C->getFalseExpr()->getType()->isVoidType())
7138 visitLocalsRetainedByReferenceBinding(Path, C->getFalseExpr(), RK, Visit,
7139 EnableLifetimeWarnings);
7140 break;
7141 }
7142
7143 // FIXME: Visit the left-hand side of an -> or ->*.
7144
7145 default:
7146 break;
7147 }
7148}
7149
7150/// Visit the locals that would be reachable through an object initialized by
7151/// the prvalue expression \c Init.
7152static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
7153 Expr *Init, LocalVisitor Visit,
7154 bool RevisitSubinits,
7155 bool EnableLifetimeWarnings) {
7156 RevertToOldSizeRAII RAII(Path);
7157
7158 Expr *Old;
7159 do {
7160 Old = Init;
7161
7162 // Step into CXXDefaultInitExprs so we can diagnose cases where a
7163 // constructor inherits one as an implicit mem-initializer.
7164 if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
7165 Path.push_back({IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
7166 Init = DIE->getExpr();
7167 }
7168
7169 if (auto *FE = dyn_cast<FullExpr>(Init))
7170 Init = FE->getSubExpr();
7171
7172 // Dig out the expression which constructs the extended temporary.
7173 Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());
7174
7175 if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
7176 Init = BTE->getSubExpr();
7177
7178 Init = Init->IgnoreParens();
7179
7180 // Step over value-preserving rvalue casts.
7181 if (auto *CE = dyn_cast<CastExpr>(Init)) {
7182 switch (CE->getCastKind()) {
7183 case CK_LValueToRValue:
7184 // If we can match the lvalue to a const object, we can look at its
7185 // initializer.
7186 Path.push_back({IndirectLocalPathEntry::LValToRVal, CE});
7187 return visitLocalsRetainedByReferenceBinding(
7188 Path, Init, RK_ReferenceBinding,
7189 [&](IndirectLocalPath &Path, Local L, ReferenceKind RK) -> bool {
7190 if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
7191 auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
7192 if (VD && VD->getType().isConstQualified() && VD->getInit() &&
7193 !isVarOnPath(Path, VD)) {
7194 Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
7195 visitLocalsRetainedByInitializer(Path, VD->getInit(), Visit, true,
7196 EnableLifetimeWarnings);
7197 }
7198 } else if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L)) {
7199 if (MTE->getType().isConstQualified())
7200 visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit,
7201 true, EnableLifetimeWarnings);
7202 }
7203 return false;
7204 }, EnableLifetimeWarnings);
7205
7206 // We assume that objects can be retained by pointers cast to integers,
7207 // but not if the integer is cast to floating-point type or to _Complex.
7208 // We assume that casts to 'bool' do not preserve enough information to
7209 // retain a local object.
7210 case CK_NoOp:
7211 case CK_BitCast:
7212 case CK_BaseToDerived:
7213 case CK_DerivedToBase:
7214 case CK_UncheckedDerivedToBase:
7215 case CK_Dynamic:
7216 case CK_ToUnion:
7217 case CK_UserDefinedConversion:
7218 case CK_ConstructorConversion:
7219 case CK_IntegralToPointer:
7220 case CK_PointerToIntegral:
7221 case CK_VectorSplat:
7222 case CK_IntegralCast:
7223 case CK_CPointerToObjCPointerCast:
7224 case CK_BlockPointerToObjCPointerCast:
7225 case CK_AnyPointerToBlockPointerCast:
7226 case CK_AddressSpaceConversion:
7227 break;
7228
7229 case CK_ArrayToPointerDecay:
7230 // Model array-to-pointer decay as taking the address of the array
7231 // lvalue.
7232 Path.push_back({IndirectLocalPathEntry::AddressOf, CE});
7233 return visitLocalsRetainedByReferenceBinding(Path, CE->getSubExpr(),
7234 RK_ReferenceBinding, Visit,
7235 EnableLifetimeWarnings);
7236
7237 default:
7238 return;
7239 }
7240
7241 Init = CE->getSubExpr();
7242 }
7243 } while (Old != Init);
7244
7245 // C++17 [dcl.init.list]p6:
7246 // initializing an initializer_list object from the array extends the
7247 // lifetime of the array exactly like binding a reference to a temporary.
7248 if (auto *ILE = dyn_cast<CXXStdInitializerListExpr>(Init))
7249 return visitLocalsRetainedByReferenceBinding(Path, ILE->getSubExpr(),
7250 RK_StdInitializerList, Visit,
7251 EnableLifetimeWarnings);
7252
7253 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
7254 // We already visited the elements of this initializer list while
7255 // performing the initialization. Don't visit them again unless we've
7256 // changed the lifetime of the initialized entity.
7257 if (!RevisitSubinits)
7258 return;
7259
7260 if (ILE->isTransparent())
7261 return visitLocalsRetainedByInitializer(Path, ILE->getInit(0), Visit,
7262 RevisitSubinits,
7263 EnableLifetimeWarnings);
7264
7265 if (ILE->getType()->isArrayType()) {
7266 for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
7267 visitLocalsRetainedByInitializer(Path, ILE->getInit(I), Visit,
7268 RevisitSubinits,
7269 EnableLifetimeWarnings);
7270 return;
7271 }
7272
7273 if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
7274 assert(RD->isAggregate() && "aggregate init on non-aggregate");
7275
7276 // If we lifetime-extend a braced initializer which is initializing an
7277 // aggregate, and that aggregate contains reference members which are
7278 // bound to temporaries, those temporaries are also lifetime-extended.
7279 if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
7280 ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
7281 visitLocalsRetainedByReferenceBinding(Path, ILE->getInit(0),
7282 RK_ReferenceBinding, Visit,
7283 EnableLifetimeWarnings);
7284 else {
7285 unsigned Index = 0;
7286 for (; Index < RD->getNumBases() && Index < ILE->getNumInits(); ++Index)
7287 visitLocalsRetainedByInitializer(Path, ILE->getInit(Index), Visit,
7288 RevisitSubinits,
7289 EnableLifetimeWarnings);
7290 for (const auto *I : RD->fields()) {
7291 if (Index >= ILE->getNumInits())
7292 break;
7293 if (I->isUnnamedBitfield())
7294 continue;
7295 Expr *SubInit = ILE->getInit(Index);
7296 if (I->getType()->isReferenceType())
7297 visitLocalsRetainedByReferenceBinding(Path, SubInit,
7298 RK_ReferenceBinding, Visit,
7299 EnableLifetimeWarnings);
7300 else
7301 // This might be either aggregate-initialization of a member or
7302 // initialization of a std::initializer_list object. Regardless,
7303 // we should recursively lifetime-extend that initializer.
7304 visitLocalsRetainedByInitializer(Path, SubInit, Visit,
7305 RevisitSubinits,
7306 EnableLifetimeWarnings);
7307 ++Index;
7308 }
7309 }
7310 }
7311 return;
7312 }
7313
7314 // The lifetime of an init-capture is that of the closure object constructed
7315 // by a lambda-expression.
7316 if (auto *LE = dyn_cast<LambdaExpr>(Init)) {
7317 LambdaExpr::capture_iterator CapI = LE->capture_begin();
7318 for (Expr *E : LE->capture_inits()) {
7319 assert(CapI != LE->capture_end());
7320 const LambdaCapture &Cap = *CapI++;
7321 if (!E)
7322 continue;
7323 if (Cap.capturesVariable())
7324 Path.push_back({IndirectLocalPathEntry::LambdaCaptureInit, E, &Cap});
7325 if (E->isGLValue())
7326 visitLocalsRetainedByReferenceBinding(Path, E, RK_ReferenceBinding,
7327 Visit, EnableLifetimeWarnings);
7328 else
7329 visitLocalsRetainedByInitializer(Path, E, Visit, true,
7330 EnableLifetimeWarnings);
7331 if (Cap.capturesVariable())
7332 Path.pop_back();
7333 }
7334 }
7335
7336 // Assume that a copy or move from a temporary references the same objects
7337 // that the temporary does.
7338 if (auto *CCE = dyn_cast<CXXConstructExpr>(Init)) {
7339 if (CCE->getConstructor()->isCopyOrMoveConstructor()) {
7340 if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(CCE->getArg(0))) {
7341 Expr *Arg = MTE->getSubExpr();
7342 Path.push_back({IndirectLocalPathEntry::TemporaryCopy, Arg,
7343 CCE->getConstructor()});
7344 visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
7345 /*EnableLifetimeWarnings*/false);
7346 Path.pop_back();
7347 }
7348 }
7349 }
7350
7351 if (isa<CallExpr>(Init) || isa<CXXConstructExpr>(Init)) {
7352 if (EnableLifetimeWarnings)
7353 handleGslAnnotatedTypes(Path, Init, Visit);
7354 return visitLifetimeBoundArguments(Path, Init, Visit);
7355 }
7356
7357 switch (Init->getStmtClass()) {
7358 case Stmt::UnaryOperatorClass: {
7359 auto *UO = cast<UnaryOperator>(Init);
7360 // If the initializer is the address of a local, we could have a lifetime
7361 // problem.
7362 if (UO->getOpcode() == UO_AddrOf) {
7363 // If this is &rvalue, then it's ill-formed and we have already diagnosed
7364 // it. Don't produce a redundant warning about the lifetime of the
7365 // temporary.
7366 if (isa<MaterializeTemporaryExpr>(UO->getSubExpr()))
7367 return;
7368
7369 Path.push_back({IndirectLocalPathEntry::AddressOf, UO});
7370 visitLocalsRetainedByReferenceBinding(Path, UO->getSubExpr(),
7371 RK_ReferenceBinding, Visit,
7372 EnableLifetimeWarnings);
7373 }
7374 break;
7375 }
7376
7377 case Stmt::BinaryOperatorClass: {
7378 // Handle pointer arithmetic.
7379 auto *BO = cast<BinaryOperator>(Init);
7380 BinaryOperatorKind BOK = BO->getOpcode();
7381 if (!BO->getType()->isPointerType() || (BOK != BO_Add && BOK != BO_Sub))
7382 break;
7383
7384 if (BO->getLHS()->getType()->isPointerType())
7385 visitLocalsRetainedByInitializer(Path, BO->getLHS(), Visit, true,
7386 EnableLifetimeWarnings);
7387 else if (BO->getRHS()->getType()->isPointerType())
7388 visitLocalsRetainedByInitializer(Path, BO->getRHS(), Visit, true,
7389 EnableLifetimeWarnings);
7390 break;
7391 }
7392
7393 case Stmt::ConditionalOperatorClass:
7394 case Stmt::BinaryConditionalOperatorClass: {
7395 auto *C = cast<AbstractConditionalOperator>(Init);
7396 // In C++, we can have a throw-expression operand, which has 'void' type
7397 // and isn't interesting from a lifetime perspective.
7398 if (!C->getTrueExpr()->getType()->isVoidType())
7399 visitLocalsRetainedByInitializer(Path, C->getTrueExpr(), Visit, true,
7400 EnableLifetimeWarnings);
7401 if (!C->getFalseExpr()->getType()->isVoidType())
7402 visitLocalsRetainedByInitializer(Path, C->getFalseExpr(), Visit, true,
7403 EnableLifetimeWarnings);
7404 break;
7405 }
7406
7407 case Stmt::BlockExprClass:
7408 if (cast<BlockExpr>(Init)->getBlockDecl()->hasCaptures()) {
7409 // This is a local block, whose lifetime is that of the function.
7410 Visit(Path, Local(cast<BlockExpr>(Init)), RK_ReferenceBinding);
7411 }
7412 break;
7413
7414 case Stmt::AddrLabelExprClass:
7415 // We want to warn if the address of a label would escape the function.
7416 Visit(Path, Local(cast<AddrLabelExpr>(Init)), RK_ReferenceBinding);
7417 break;
7418
7419 default:
7420 break;
7421 }
7422}
7423
7424/// Whether a path to an object supports lifetime extension.
7425enum PathLifetimeKind {
7426 /// Lifetime-extend along this path.
7427 Extend,
7428 /// We should lifetime-extend, but we don't because (due to technical
7429 /// limitations) we can't. This happens for default member initializers,
7430 /// which we don't clone for every use, so we don't have a unique
7431 /// MaterializeTemporaryExpr to update.
7432 ShouldExtend,
7433 /// Do not lifetime extend along this path.
7434 NoExtend
7435};
7436
7437/// Determine whether this is an indirect path to a temporary that we are
7438/// supposed to lifetime-extend along.
7439static PathLifetimeKind
7440shouldLifetimeExtendThroughPath(const IndirectLocalPath &Path) {
7441 PathLifetimeKind Kind = PathLifetimeKind::Extend;
7442 for (auto Elem : Path) {
7443 if (Elem.Kind == IndirectLocalPathEntry::DefaultInit)
7444 Kind = PathLifetimeKind::ShouldExtend;
7445 else if (Elem.Kind != IndirectLocalPathEntry::LambdaCaptureInit)
7446 return PathLifetimeKind::NoExtend;
7447 }
7448 return Kind;
7449}
7450
7451/// Find the range for the first interesting entry in the path at or after I.
7452static SourceRange nextPathEntryRange(const IndirectLocalPath &Path, unsigned I,
7453 Expr *E) {
7454 for (unsigned N = Path.size(); I != N; ++I) {
7455 switch (Path[I].Kind) {
7456 case IndirectLocalPathEntry::AddressOf:
7457 case IndirectLocalPathEntry::LValToRVal:
7458 case IndirectLocalPathEntry::LifetimeBoundCall:
7459 case IndirectLocalPathEntry::TemporaryCopy:
7460 case IndirectLocalPathEntry::GslReferenceInit:
7461 case IndirectLocalPathEntry::GslPointerInit:
7462 // These exist primarily to mark the path as not permitting or
7463 // supporting lifetime extension.
7464 break;
7465
7466 case IndirectLocalPathEntry::VarInit:
7467 if (cast<VarDecl>(Path[I].D)->isImplicit())
7468 return SourceRange();
7469 LLVM_FALLTHROUGH;
7470 case IndirectLocalPathEntry::DefaultInit:
7471 return Path[I].E->getSourceRange();
7472
7473 case IndirectLocalPathEntry::LambdaCaptureInit:
7474 if (!Path[I].Capture->capturesVariable())
7475 continue;
7476 return Path[I].E->getSourceRange();
7477 }
7478 }
7479 return E->getSourceRange();
7480}
7481
7482static bool pathOnlyInitializesGslPointer(IndirectLocalPath &Path) {
7483 for (auto It = Path.rbegin(), End = Path.rend(); It != End; ++It) {
7484 if (It->Kind == IndirectLocalPathEntry::VarInit)
7485 continue;
7486 if (It->Kind == IndirectLocalPathEntry::AddressOf)
7487 continue;
7488 return It->Kind == IndirectLocalPathEntry::GslPointerInit ||
7489 It->Kind == IndirectLocalPathEntry::GslReferenceInit;
7490 }
7491 return false;
7492}
7493
7494void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
7495 Expr *Init) {
7496 LifetimeResult LR = getEntityLifetime(&Entity);
7497 LifetimeKind LK = LR.getInt();
7498 const InitializedEntity *ExtendingEntity = LR.getPointer();
7499
7500 // If this entity doesn't have an interesting lifetime, don't bother looking
7501 // for temporaries within its initializer.
7502 if (LK == LK_FullExpression)
7503 return;
7504
7505 auto TemporaryVisitor = [&](IndirectLocalPath &Path, Local L,
7506 ReferenceKind RK) -> bool {
7507 SourceRange DiagRange = nextPathEntryRange(Path, 0, L);
7508 SourceLocation DiagLoc = DiagRange.getBegin();
7509
7510 auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L);
7511
7512 bool IsGslPtrInitWithGslTempOwner = false;
7513 bool IsLocalGslOwner = false;
7514 if (pathOnlyInitializesGslPointer(Path)) {
7515 if (isa<DeclRefExpr>(L)) {
7516 // We do not want to follow the references when returning a pointer originating
7517 // from a local owner to avoid the following false positive:
7518 // int &p = *localUniquePtr;
7519 // someContainer.add(std::move(localUniquePtr));
7520 // return p;
7521 IsLocalGslOwner = isRecordWithAttr<OwnerAttr>(L->getType());
7522 if (pathContainsInit(Path) || !IsLocalGslOwner)
7523 return false;
7524 } else {
7525 IsGslPtrInitWithGslTempOwner = MTE && !MTE->getExtendingDecl() &&
7526 isRecordWithAttr<OwnerAttr>(MTE->getType());
7527 // Skipping a chain of initializing gsl::Pointer annotated objects.
7528 // We are looking only for the final source to find out if it was
7529 // a local or temporary owner or the address of a local variable/param.
7530 if (!IsGslPtrInitWithGslTempOwner)
7531 return true;
7532 }
7533 }
7534
7535 switch (LK) {
7536 case LK_FullExpression:
7537 llvm_unreachable("already handled this");
7538
7539 case LK_Extended: {
7540 if (!MTE) {
7541 // The initialized entity has lifetime beyond the full-expression,
7542 // and the local entity does too, so don't warn.
7543 //
7544 // FIXME: We should consider warning if a static / thread storage
7545 // duration variable retains an automatic storage duration local.
7546 return false;
7547 }
7548
7549 if (IsGslPtrInitWithGslTempOwner && DiagLoc.isValid()) {
7550 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
7551 return false;
7552 }
7553
7554 switch (shouldLifetimeExtendThroughPath(Path)) {
7555 case PathLifetimeKind::Extend:
7556 // Update the storage duration of the materialized temporary.
7557 // FIXME: Rebuild the expression instead of mutating it.
7558 MTE->setExtendingDecl(ExtendingEntity->getDecl(),
7559 ExtendingEntity->allocateManglingNumber());
7560 // Also visit the temporaries lifetime-extended by this initializer.
7561 return true;
7562
7563 case PathLifetimeKind::ShouldExtend:
7564 // We're supposed to lifetime-extend the temporary along this path (per
7565 // the resolution of DR1815), but we don't support that yet.
7566 //
7567 // FIXME: Properly handle this situation. Perhaps the easiest approach
7568 // would be to clone the initializer expression on each use that would
7569 // lifetime extend its temporaries.
7570 Diag(DiagLoc, diag::warn_unsupported_lifetime_extension)
7571 << RK << DiagRange;
7572 break;
7573
7574 case PathLifetimeKind::NoExtend:
7575 // If the path goes through the initialization of a variable or field,
7576 // it can't possibly reach a temporary created in this full-expression.
7577 // We will have already diagnosed any problems with the initializer.
7578 if (pathContainsInit(Path))
7579 return false;
7580
7581 Diag(DiagLoc, diag::warn_dangling_variable)
7582 << RK << !Entity.getParent()
7583 << ExtendingEntity->getDecl()->isImplicit()
7584 << ExtendingEntity->getDecl() << Init->isGLValue() << DiagRange;
7585 break;
7586 }
7587 break;
7588 }
7589
7590 case LK_MemInitializer: {
7591 if (isa<MaterializeTemporaryExpr>(L)) {
7592 // Under C++ DR1696, if a mem-initializer (or a default member
7593 // initializer used by the absence of one) would lifetime-extend a
7594 // temporary, the program is ill-formed.
7595 if (auto *ExtendingDecl =
7596 ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
7597 if (IsGslPtrInitWithGslTempOwner) {
7598 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer_member)
7599 << ExtendingDecl << DiagRange;
7600 Diag(ExtendingDecl->getLocation(),
7601 diag::note_ref_or_ptr_member_declared_here)
7602 << true;
7603 return false;
7604 }
7605 bool IsSubobjectMember = ExtendingEntity != &Entity;
7606 Diag(DiagLoc, shouldLifetimeExtendThroughPath(Path) !=
7607 PathLifetimeKind::NoExtend
7608 ? diag::err_dangling_member
7609 : diag::warn_dangling_member)
7610 << ExtendingDecl << IsSubobjectMember << RK << DiagRange;
7611 // Don't bother adding a note pointing to the field if we're inside
7612 // its default member initializer; our primary diagnostic points to
7613 // the same place in that case.
7614 if (Path.empty() ||
7615 Path.back().Kind != IndirectLocalPathEntry::DefaultInit) {
7616 Diag(ExtendingDecl->getLocation(),
7617 diag::note_lifetime_extending_member_declared_here)
7618 << RK << IsSubobjectMember;
7619 }
7620 } else {
7621 // We have a mem-initializer but no particular field within it; this
7622 // is either a base class or a delegating initializer directly
7623 // initializing the base-class from something that doesn't live long
7624 // enough.
7625 //
7626 // FIXME: Warn on this.
7627 return false;
7628 }
7629 } else {
7630 // Paths via a default initializer can only occur during error recovery
7631 // (there's no other way that a default initializer can refer to a
7632 // local). Don't produce a bogus warning on those cases.
7633 if (pathContainsInit(Path))
7634 return false;
7635
7636 // Suppress false positives for code like the one below:
7637 // Ctor(unique_ptr<T> up) : member(*up), member2(move(up)) {}
7638 if (IsLocalGslOwner && pathOnlyInitializesGslPointer(Path))
7639 return false;
7640
7641 auto *DRE = dyn_cast<DeclRefExpr>(L);
7642 auto *VD = DRE ? dyn_cast<VarDecl>(DRE->getDecl()) : nullptr;
7643 if (!VD) {
7644 // A member was initialized to a local block.
7645 // FIXME: Warn on this.
7646 return false;
7647 }
7648
7649 if (auto *Member =
7650 ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
7651 bool IsPointer = !Member->getType()->isReferenceType();
7652 Diag(DiagLoc, IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
7653 : diag::warn_bind_ref_member_to_parameter)
7654 << Member << VD << isa<ParmVarDecl>(VD) << DiagRange;
7655 Diag(Member->getLocation(),
7656 diag::note_ref_or_ptr_member_declared_here)
7657 << (unsigned)IsPointer;
7658 }
7659 }
7660 break;
7661 }
7662
7663 case LK_New:
7664 if (isa<MaterializeTemporaryExpr>(L)) {
7665 if (IsGslPtrInitWithGslTempOwner)
7666 Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
7667 else
7668 Diag(DiagLoc, RK == RK_ReferenceBinding
7669 ? diag::warn_new_dangling_reference
7670 : diag::warn_new_dangling_initializer_list)
7671 << !Entity.getParent() << DiagRange;
7672 } else {
7673 // We can't determine if the allocation outlives the local declaration.
7674 return false;
7675 }
7676 break;
7677
7678 case LK_Return:
7679 case LK_StmtExprResult:
7680 if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
7681 // We can't determine if the local variable outlives the statement
7682 // expression.
7683 if (LK == LK_StmtExprResult)
7684 return false;
7685 Diag(DiagLoc, diag::warn_ret_stack_addr_ref)
7686 << Entity.getType()->isReferenceType() << DRE->getDecl()
7687 << isa<ParmVarDecl>(DRE->getDecl()) << DiagRange;
7688 } else if (isa<BlockExpr>(L)) {
7689 Diag(DiagLoc, diag::err_ret_local_block) << DiagRange;
7690 } else if (isa<AddrLabelExpr>(L)) {
7691 // Don't warn when returning a label from a statement expression.
7692 // Leaving the scope doesn't end its lifetime.
7693 if (LK == LK_StmtExprResult)
7694 return false;
7695 Diag(DiagLoc, diag::warn_ret_addr_label) << DiagRange;
7696 } else {
7697 Diag(DiagLoc, diag::warn_ret_local_temp_addr_ref)
7698 << Entity.getType()->isReferenceType() << DiagRange;
7699 }
7700 break;
7701 }
7702
7703 for (unsigned I = 0; I != Path.size(); ++I) {
7704 auto Elem = Path[I];
7705
7706 switch (Elem.Kind) {
7707 case IndirectLocalPathEntry::AddressOf:
7708 case IndirectLocalPathEntry::LValToRVal:
7709 // These exist primarily to mark the path as not permitting or
7710 // supporting lifetime extension.
7711 break;
7712
7713 case IndirectLocalPathEntry::LifetimeBoundCall:
7714 case IndirectLocalPathEntry::TemporaryCopy:
7715 case IndirectLocalPathEntry::GslPointerInit:
7716 case IndirectLocalPathEntry::GslReferenceInit:
7717 // FIXME: Consider adding a note for these.
7718 break;
7719
7720 case IndirectLocalPathEntry::DefaultInit: {
7721 auto *FD = cast<FieldDecl>(Elem.D);
7722 Diag(FD->getLocation(), diag::note_init_with_default_member_initalizer)
7723 << FD << nextPathEntryRange(Path, I + 1, L);
7724 break;
7725 }
7726
7727 case IndirectLocalPathEntry::VarInit: {
7728 const VarDecl *VD = cast<VarDecl>(Elem.D);
7729 Diag(VD->getLocation(), diag::note_local_var_initializer)
7730 << VD->getType()->isReferenceType()
7731 << VD->isImplicit() << VD->getDeclName()
7732 << nextPathEntryRange(Path, I + 1, L);
7733 break;
7734 }
7735
7736 case IndirectLocalPathEntry::LambdaCaptureInit:
7737 if (!Elem.Capture->capturesVariable())
7738 break;
7739 // FIXME: We can't easily tell apart an init-capture from a nested
7740 // capture of an init-capture.
7741 const VarDecl *VD = Elem.Capture->getCapturedVar();
7742 Diag(Elem.Capture->getLocation(), diag::note_lambda_capture_initializer)
7743 << VD << VD->isInitCapture() << Elem.Capture->isExplicit()
7744 << (Elem.Capture->getCaptureKind() == LCK_ByRef) << VD
7745 << nextPathEntryRange(Path, I + 1, L);
7746 break;
7747 }
7748 }
7749
7750 // We didn't lifetime-extend, so don't go any further; we don't need more
7751 // warnings or errors on inner temporaries within this one's initializer.
7752 return false;
7753 };
7754
7755 bool EnableLifetimeWarnings = !getDiagnostics().isIgnored(
7756 diag::warn_dangling_lifetime_pointer, SourceLocation());
7757 llvm::SmallVector<IndirectLocalPathEntry, 8> Path;
7758 if (Init->isGLValue())
7759 visitLocalsRetainedByReferenceBinding(Path, Init, RK_ReferenceBinding,
7760 TemporaryVisitor,
7761 EnableLifetimeWarnings);
7762 else
7763 visitLocalsRetainedByInitializer(Path, Init, TemporaryVisitor, false,
7764 EnableLifetimeWarnings);
7765}
7766
7767static void DiagnoseNarrowingInInitList(Sema &S,
7768 const ImplicitConversionSequence &ICS,
7769 QualType PreNarrowingType,
7770 QualType EntityType,
7771 const Expr *PostInit);
7772
7773/// Provide warnings when std::move is used on construction.
7774static void CheckMoveOnConstruction(Sema &S, const Expr *InitExpr,
7775 bool IsReturnStmt) {
7776 if (!InitExpr)
7777 return;
7778
7779 if (S.inTemplateInstantiation())
7780 return;
7781
7782 QualType DestType = InitExpr->getType();
7783 if (!DestType->isRecordType())
7784 return;
7785
7786 unsigned DiagID = 0;
7787 if (IsReturnStmt) {
7788 const CXXConstructExpr *CCE =
7789 dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
7790 if (!CCE || CCE->getNumArgs() != 1)
7791 return;
7792
7793 if (!CCE->getConstructor()->isCopyOrMoveConstructor())
7794 return;
7795
7796 InitExpr = CCE->getArg(0)->IgnoreImpCasts();
7797 }
7798
7799 // Find the std::move call and get the argument.
7800 const CallExpr *CE = dyn_cast<CallExpr>(InitExpr->IgnoreParens());
7801 if (!CE || !CE->isCallToStdMove())
7802 return;
7803
7804 const Expr *Arg = CE->getArg(0)->IgnoreImplicit();
7805
7806 if (IsReturnStmt) {
7807 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts());
7808 if (!DRE || DRE->refersToEnclosingVariableOrCapture())
7809 return;
7810
7811 const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl());
7812 if (!VD || !VD->hasLocalStorage())
7813 return;
7814
7815 // __block variables are not moved implicitly.
7816 if (VD->hasAttr<BlocksAttr>())
7817 return;
7818
7819 QualType SourceType = VD->getType();
7820 if (!SourceType->isRecordType())
7821 return;
7822
7823 if (!S.Context.hasSameUnqualifiedType(DestType, SourceType)) {
7824 return;
7825 }
7826
7827 // If we're returning a function parameter, copy elision
7828 // is not possible.
7829 if (isa<ParmVarDecl>(VD))
7830 DiagID = diag::warn_redundant_move_on_return;
7831 else
7832 DiagID = diag::warn_pessimizing_move_on_return;
7833 } else {
7834 DiagID = diag::warn_pessimizing_move_on_initialization;
7835 const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
7836 if (!ArgStripped->isRValue() || !ArgStripped->getType()->isRecordType())
7837 return;
7838 }
7839
7840 S.Diag(CE->getBeginLoc(), DiagID);
7841
7842 // Get all the locations for a fix-it. Don't emit the fix-it if any location
7843 // is within a macro.
7844 SourceLocation CallBegin = CE->getCallee()->getBeginLoc();
7845 if (CallBegin.isMacroID())
7846 return;
7847 SourceLocation RParen = CE->getRParenLoc();
7848 if (RParen.isMacroID())
7849 return;
7850 SourceLocation LParen;
7851 SourceLocation ArgLoc = Arg->getBeginLoc();
7852
7853 // Special testing for the argument location. Since the fix-it needs the
7854 // location right before the argument, the argument location can be in a
7855 // macro only if it is at the beginning of the macro.
7856 while (ArgLoc.isMacroID() &&
7857 S.getSourceManager().isAtStartOfImmediateMacroExpansion(ArgLoc)) {
7858 ArgLoc = S.getSourceManager().getImmediateExpansionRange(ArgLoc).getBegin();
7859 }
7860
7861 if (LParen.isMacroID())
7862 return;
7863
7864 LParen = ArgLoc.getLocWithOffset(-1);
7865
7866 S.Diag(CE->getBeginLoc(), diag::note_remove_move)
7867 << FixItHint::CreateRemoval(SourceRange(CallBegin, LParen))
7868 << FixItHint::CreateRemoval(SourceRange(RParen, RParen));
7869}
7870
7871static void CheckForNullPointerDereference(Sema &S, const Expr *E) {
7872 // Check to see if we are dereferencing a null pointer. If so, this is
7873 // undefined behavior, so warn about it. This only handles the pattern
7874 // "*null", which is a very syntactic check.
7875 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts()))
7876 if (UO->getOpcode() == UO_Deref &&
7877 UO->getSubExpr()->IgnoreParenCasts()->
7878 isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)) {
7879 S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
7880 S.PDiag(diag::warn_binding_null_to_reference)
7881 << UO->getSubExpr()->getSourceRange());
7882 }
7883}
7884
7885MaterializeTemporaryExpr *
7886Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
7887 bool BoundToLvalueReference) {
7888 auto MTE = new (Context)
7889 MaterializeTemporaryExpr(T, Temporary, BoundToLvalueReference);
7890
7891 // Order an ExprWithCleanups for lifetime marks.
7892 //
7893 // TODO: It'll be good to have a single place to check the access of the
7894 // destructor and generate ExprWithCleanups for various uses. Currently these
7895 // are done in both CreateMaterializeTemporaryExpr and MaybeBindToTemporary,
7896 // but there may be a chance to merge them.
7897 Cleanup.setExprNeedsCleanups(false);
7898 return MTE;
7899}
7900
7901ExprResult Sema::TemporaryMaterializationConversion(Expr *E) {
7902 // In C++98, we don't want to implicitly create an xvalue.
7903 // FIXME: This means that AST consumers need to deal with "prvalues" that
7904 // denote materialized temporaries. Maybe we should add another ValueKind
7905 // for "xvalue pretending to be a prvalue" for C++98 support.
7906 if (!E->isRValue() || !getLangOpts().CPlusPlus11)
7907 return E;
7908
7909 // C++1z [conv.rval]/1: T shall be a complete type.
7910 // FIXME: Does this ever matter (can we form a prvalue of incomplete type)?
7911 // If so, we should check for a non-abstract class type here too.
7912 QualType T = E->getType();
7913 if (RequireCompleteType(E->getExprLoc(), T, diag::err_incomplete_type))
7914 return ExprError();
7915
7916 return CreateMaterializeTemporaryExpr(E->getType(), E, false);
7917}
7918
7919ExprResult Sema::PerformQualificationConversion(Expr *E, QualType Ty,
7920 ExprValueKind VK,
7921 CheckedConversionKind CCK) {
7922
7923 CastKind CK = CK_NoOp;
7924
7925 if (VK == VK_RValue) {
7926 auto PointeeTy = Ty->getPointeeType();
7927 auto ExprPointeeTy = E->getType()->getPointeeType();
7928 if (!PointeeTy.isNull() &&
7929 PointeeTy.getAddressSpace() != ExprPointeeTy.getAddressSpace())
7930 CK = CK_AddressSpaceConversion;
7931 } else if (Ty.getAddressSpace() != E->getType().getAddressSpace()) {
7932 CK = CK_AddressSpaceConversion;
7933 }
7934
7935 return ImpCastExprToType(E, Ty, CK, VK, /*BasePath=*/nullptr, CCK);
7936}
7937
7938ExprResult InitializationSequence::Perform(Sema &S,
7939 const InitializedEntity &Entity,
7940 const InitializationKind &Kind,
7941 MultiExprArg Args,
7942 QualType *ResultType) {
7943 if (Failed()) {
7944 Diagnose(S, Entity, Kind, Args);
7945 return ExprError();
7946 }
7947 if (!ZeroInitializationFixit.empty()) {
7948 unsigned DiagID = diag::err_default_init_const;
7949 if (Decl *D = Entity.getDecl())
7950 if (S.getLangOpts().MSVCCompat && D->hasAttr<SelectAnyAttr>())
7951 DiagID = diag::ext_default_init_const;
7952
7953 // The initialization would have succeeded with this fixit. Since the fixit
7954 // is on the error, we need to build a valid AST in this case, so this isn't
7955 // handled in the Failed() branch above.
7956 QualType DestType = Entity.getType();
7957 S.Diag(Kind.getLocation(), DiagID)
7958 << DestType << (bool)DestType->getAs<RecordType>()
7959 << FixItHint::CreateInsertion(ZeroInitializationFixitLoc,
7960 ZeroInitializationFixit);
7961 }
7962
7963 if (getKind() == DependentSequence) {
7964 // If the declaration is a non-dependent, incomplete array type
7965 // that has an initializer, then its type will be completed once
7966 // the initializer is instantiated.
7967 if (ResultType && !Entity.getType()->isDependentType() &&
7968 Args.size() == 1) {
7969 QualType DeclType = Entity.getType();
7970 if (const IncompleteArrayType *ArrayT
7971 = S.Context.getAsIncompleteArrayType(DeclType)) {
7972 // FIXME: We don't currently have the ability to accurately
7973 // compute the length of an initializer list without
7974 // performing full type-checking of the initializer list
7975 // (since we have to determine where braces are implicitly
7976 // introduced and such). So, we fall back to making the array
7977 // type a dependently-sized array type with no specified
7978 // bound.
7979 if (isa<InitListExpr>((Expr *)Args[0])) {
7980 SourceRange Brackets;
7981
7982 // Scavange the location of the brackets from the entity, if we can.
7983 if (auto *DD = dyn_cast_or_null<DeclaratorDecl>(Entity.getDecl())) {
7984 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) {
7985 TypeLoc TL = TInfo->getTypeLoc();
7986 if (IncompleteArrayTypeLoc ArrayLoc =
7987 TL.getAs<IncompleteArrayTypeLoc>())
7988 Brackets = ArrayLoc.getBracketsRange();
7989 }
7990 }
7991
7992 *ResultType
7993 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
7994 /*NumElts=*/nullptr,
7995 ArrayT->getSizeModifier(),
7996 ArrayT->getIndexTypeCVRQualifiers(),
7997 Brackets);
7998 }
7999
8000 }
8001 }
8002 if (Kind.getKind() == InitializationKind::IK_Direct &&
8003 !Kind.isExplicitCast()) {
8004 // Rebuild the ParenListExpr.
8005 SourceRange ParenRange = Kind.getParenOrBraceRange();
8006 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(),
8007 Args);
8008 }
8009 assert(Kind.getKind() == InitializationKind::IK_Copy ||
8010 Kind.isExplicitCast() ||
8011 Kind.getKind() == InitializationKind::IK_DirectList);
8012 return ExprResult(Args[0]);
8013 }
8014
8015 // No steps means no initialization.
8016 if (Steps.empty())
8017 return ExprResult((Expr *)nullptr);
8018
8019 if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() &&
8020 Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
8021 !Entity.isParamOrTemplateParamKind()) {
8022 // Produce a C++98 compatibility warning if we are initializing a reference
8023 // from an initializer list. For parameters, we produce a better warning
8024 // elsewhere.
8025 Expr *Init = Args[0];
8026 S.Diag(Init->getBeginLoc(), diag::warn_cxx98_compat_reference_list_init)
8027 << Init->getSourceRange();
8028 }
8029
8030 // OpenCL v2.0 s6.13.11.1. atomic variables can be initialized in global scope
8031 QualType ETy = Entity.getType();
8032 bool HasGlobalAS = ETy.hasAddressSpace() &&
8033 ETy.getAddressSpace() == LangAS::opencl_global;
8034
8035 if (S.getLangOpts().OpenCLVersion >= 200 &&
8036 ETy->isAtomicType() && !HasGlobalAS &&
8037 Entity.getKind() == InitializedEntity::EK_Variable && Args.size() > 0) {
8038 S.Diag(Args[0]->getBeginLoc(), diag::err_opencl_atomic_init)
8039 << 1
8040 << SourceRange(Entity.getDecl()->getBeginLoc(), Args[0]->getEndLoc());
8041 return ExprError();
8042 }
8043
8044 QualType DestType = Entity.getType().getNonReferenceType();
8045 // FIXME: Ugly hack around the fact that Entity.getType() is not
8046 // the same as Entity.getDecl()->getType() in cases involving type merging,
8047 // and we want latter when it makes sense.
8048 if (ResultType)
8049 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() :
8050 Entity.getType();
8051
8052 ExprResult CurInit((Expr *)nullptr);
8053 SmallVector<Expr*, 4> ArrayLoopCommonExprs;
8054
8055 // For initialization steps that start with a single initializer,
8056 // grab the only argument out the Args and place it into the "current"
8057 // initializer.
8058 switch (Steps.front().Kind) {
8059 case SK_ResolveAddressOfOverloadedFunction:
8060 case SK_CastDerivedToBaseRValue:
8061 case SK_CastDerivedToBaseXValue:
8062 case SK_CastDerivedToBaseLValue:
8063 case SK_BindReference:
8064 case SK_BindReferenceToTemporary:
8065 case SK_FinalCopy:
8066 case SK_ExtraneousCopyToTemporary:
8067 case SK_UserConversion:
8068 case SK_QualificationConversionLValue:
8069 case SK_QualificationConversionXValue:
8070 case SK_QualificationConversionRValue:
8071 case SK_FunctionReferenceConversion:
8072 case SK_AtomicConversion:
8073 case SK_ConversionSequence:
8074 case SK_ConversionSequenceNoNarrowing:
8075 case SK_ListInitialization:
8076 case SK_UnwrapInitList:
8077 case SK_RewrapInitList:
8078 case SK_CAssignment:
8079 case SK_StringInit:
8080 case SK_ObjCObjectConversion:
8081 case SK_ArrayLoopIndex:
8082 case SK_ArrayLoopInit:
8083 case SK_ArrayInit:
8084 case SK_GNUArrayInit:
8085 case SK_ParenthesizedArrayInit:
8086 case SK_PassByIndirectCopyRestore:
8087 case SK_PassByIndirectRestore:
8088 case SK_ProduceObjCObject:
8089 case SK_StdInitializerList:
8090 case SK_OCLSamplerInit:
8091 case SK_OCLZeroOpaqueType: {
8092 assert(Args.size() == 1);
8093 CurInit = Args[0];
8094 if (!CurInit.get()) return ExprError();
8095 break;
8096 }
8097
8098 case SK_ConstructorInitialization:
8099 case SK_ConstructorInitializationFromList:
8100 case SK_StdInitializerListConstructorCall:
8101 case SK_ZeroInitialization:
8102 break;
8103 }
8104
8105 // Promote from an unevaluated context to an unevaluated list context in
8106 // C++11 list-initialization; we need to instantiate entities usable in
8107 // constant expressions here in order to perform narrowing checks =(
8108 EnterExpressionEvaluationContext Evaluated(
8109 S, EnterExpressionEvaluationContext::InitList,
8110 CurInit.get() && isa<InitListExpr>(CurInit.get()));
8111
8112 // C++ [class.abstract]p2:
8113 // no objects of an abstract class can be created except as subobjects
8114 // of a class derived from it
8115 auto checkAbstractType = [&](QualType T) -> bool {
8116 if (Entity.getKind() == InitializedEntity::EK_Base ||
8117 Entity.getKind() == InitializedEntity::EK_Delegating)
8118 return false;
8119 return S.RequireNonAbstractType(Kind.getLocation(), T,
8120 diag::err_allocation_of_abstract_type);
8121 };
8122
8123 // Walk through the computed steps for the initialization sequence,
8124 // performing the specified conversions along the way.
8125 bool ConstructorInitRequiresZeroInit = false;
8126 for (step_iterator Step = step_begin(), StepEnd = step_end();
8127 Step != StepEnd; ++Step) {
8128 if (CurInit.isInvalid())
8129 return ExprError();
8130
8131 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType();
8132
8133 switch (Step->Kind) {
8134 case SK_ResolveAddressOfOverloadedFunction:
8135 // Overload resolution determined which function invoke; update the
8136 // initializer to reflect that choice.
8137 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl);
8138 if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()))
8139 return ExprError();
8140 CurInit = S.FixOverloadedFunctionReference(CurInit,
8141 Step->Function.FoundDecl,
8142 Step->Function.Function);
8143 break;
8144
8145 case SK_CastDerivedToBaseRValue:
8146 case SK_CastDerivedToBaseXValue:
8147 case SK_CastDerivedToBaseLValue: {
8148 // We have a derived-to-base cast that produces either an rvalue or an
8149 // lvalue. Perform that cast.
8150
8151 CXXCastPath BasePath;
8152
8153 // Casts to inaccessible base classes are allowed with C-style casts.
8154 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
8155 if (S.CheckDerivedToBaseConversion(
8156 SourceType, Step->Type, CurInit.get()->getBeginLoc(),
8157 CurInit.get()->getSourceRange(), &BasePath, IgnoreBaseAccess))
8158 return ExprError();
8159
8160 ExprValueKind VK =
8161 Step->Kind == SK_CastDerivedToBaseLValue ?
8162 VK_LValue :
8163 (Step->Kind == SK_CastDerivedToBaseXValue ?
8164 VK_XValue :
8165 VK_RValue);
8166 CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
8167 CK_DerivedToBase, CurInit.get(),
8168 &BasePath, VK, FPOptionsOverride());
8169 break;
8170 }
8171
8172 case SK_BindReference:
8173 // Reference binding does not have any corresponding ASTs.
8174
8175 // Check exception specifications
8176 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
8177 return ExprError();
8178
8179 // We don't check for e.g. function pointers here, since address
8180 // availability checks should only occur when the function first decays
8181 // into a pointer or reference.
8182 if (CurInit.get()->getType()->isFunctionProtoType()) {
8183 if (auto *DRE = dyn_cast<DeclRefExpr>(CurInit.get()->IgnoreParens())) {
8184 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
8185 if (!S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
8186 DRE->getBeginLoc()))
8187 return ExprError();
8188 }
8189 }
8190 }
8191
8192 CheckForNullPointerDereference(S, CurInit.get());
8193 break;
8194
8195 case SK_BindReferenceToTemporary: {
8196 // Make sure the "temporary" is actually an rvalue.
8197 assert(CurInit.get()->isRValue() && "not a temporary");
8198
8199 // Check exception specifications
8200 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
8201 return ExprError();
8202
8203 QualType MTETy = Step->Type;
8204
8205 // When this is an incomplete array type (such as when this is
8206 // initializing an array of unknown bounds from an init list), use THAT
8207 // type instead so that we propogate the array bounds.
8208 if (MTETy->isIncompleteArrayType() &&
8209 !CurInit.get()->getType()->isIncompleteArrayType() &&
8210 S.Context.hasSameType(
8211 MTETy->getPointeeOrArrayElementType(),
8212 CurInit.get()->getType()->getPointeeOrArrayElementType()))
8213 MTETy = CurInit.get()->getType();
8214
8215 // Materialize the temporary into memory.
8216 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
8217 MTETy, CurInit.get(), Entity.getType()->isLValueReferenceType());
8218 CurInit = MTE;
8219
8220 // If we're extending this temporary to automatic storage duration -- we
8221 // need to register its cleanup during the full-expression's cleanups.
8222 if (MTE->getStorageDuration() == SD_Automatic &&
8223 MTE->getType().isDestructedType())
8224 S.Cleanup.setExprNeedsCleanups(true);
8225 break;
8226 }
8227
8228 case SK_FinalCopy:
8229 if (checkAbstractType(Step->Type))
8230 return ExprError();
8231
8232 // If the overall initialization is initializing a temporary, we already
8233 // bound our argument if it was necessary to do so. If not (if we're
8234 // ultimately initializing a non-temporary), our argument needs to be
8235 // bound since it's initializing a function parameter.
8236 // FIXME: This is a mess. Rationalize temporary destruction.
8237 if (!shouldBindAsTemporary(Entity))
8238 CurInit = S.MaybeBindToTemporary(CurInit.get());
8239 CurInit = CopyObject(S, Step->Type, Entity, CurInit,
8240 /*IsExtraneousCopy=*/false);
8241 break;
8242
8243 case SK_ExtraneousCopyToTemporary:
8244 CurInit = CopyObject(S, Step->Type, Entity, CurInit,
8245 /*IsExtraneousCopy=*/true);
8246 break;
8247
8248 case SK_UserConversion: {
8249 // We have a user-defined conversion that invokes either a constructor
8250 // or a conversion function.
8251 CastKind CastKind;
8252 FunctionDecl *Fn = Step->Function.Function;
8253 DeclAccessPair FoundFn = Step->Function.FoundDecl;
8254 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates;
8255 bool CreatedObject = false;
8256 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) {
8257 // Build a call to the selected constructor.
8258 SmallVector<Expr*, 8> ConstructorArgs;
8259 SourceLocation Loc = CurInit.get()->getBeginLoc();
8260
8261 // Determine the arguments required to actually perform the constructor
8262 // call.
8263 Expr *Arg = CurInit.get();
8264 if (S.CompleteConstructorCall(Constructor,
8265 MultiExprArg(&Arg, 1),
8266 Loc, ConstructorArgs))
8267 return ExprError();
8268
8269 // Build an expression that constructs a temporary.
8270 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type,
8271 FoundFn, Constructor,
8272 ConstructorArgs,
8273 HadMultipleCandidates,
8274 /*ListInit*/ false,
8275 /*StdInitListInit*/ false,
8276 /*ZeroInit*/ false,
8277 CXXConstructExpr::CK_Complete,
8278 SourceRange());
8279 if (CurInit.isInvalid())
8280 return ExprError();
8281
8282 S.CheckConstructorAccess(Kind.getLocation(), Constructor, FoundFn,
8283 Entity);
8284 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
8285 return ExprError();
8286
8287 CastKind = CK_ConstructorConversion;
8288 CreatedObject = true;
8289 } else {
8290 // Build a call to the conversion function.
8291 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn);
8292 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr,
8293 FoundFn);
8294 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
8295 return ExprError();
8296
8297 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion,
8298 HadMultipleCandidates);
8299 if (CurInit.isInvalid())
8300 return ExprError();
8301
8302 CastKind = CK_UserDefinedConversion;
8303 CreatedObject = Conversion->getReturnType()->isRecordType();
8304 }
8305
8306 if (CreatedObject && checkAbstractType(CurInit.get()->getType()))
8307 return ExprError();
8308
8309 CurInit = ImplicitCastExpr::Create(
8310 S.Context, CurInit.get()->getType(), CastKind, CurInit.get(), nullptr,
8311 CurInit.get()->getValueKind(), S.CurFPFeatureOverrides());
8312
8313 if (shouldBindAsTemporary(Entity))
8314 // The overall entity is temporary, so this expression should be
8315 // destroyed at the end of its full-expression.
8316 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
8317 else if (CreatedObject && shouldDestroyEntity(Entity)) {
8318 // The object outlasts the full-expression, but we need to prepare for
8319 // a destructor being run on it.
8320 // FIXME: It makes no sense to do this here. This should happen
8321 // regardless of how we initialized the entity.
8322 QualType T = CurInit.get()->getType();
8323 if (const RecordType *Record = T->getAs<RecordType>()) {
8324 CXXDestructorDecl *Destructor
8325 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl()));
8326 S.CheckDestructorAccess(CurInit.get()->getBeginLoc(), Destructor,
8327 S.PDiag(diag::err_access_dtor_temp) << T);
8328 S.MarkFunctionReferenced(CurInit.get()->getBeginLoc(), Destructor);
8329 if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getBeginLoc()))
8330 return ExprError();
8331 }
8332 }
8333 break;
8334 }
8335
8336 case SK_QualificationConversionLValue:
8337 case SK_QualificationConversionXValue:
8338 case SK_QualificationConversionRValue: {
8339 // Perform a qualification conversion; these can never go wrong.
8340 ExprValueKind VK =
8341 Step->Kind == SK_QualificationConversionLValue
8342 ? VK_LValue
8343 : (Step->Kind == SK_QualificationConversionXValue ? VK_XValue
8344 : VK_RValue);
8345 CurInit = S.PerformQualificationConversion(CurInit.get(), Step->Type, VK);
8346 break;
8347 }
8348
8349 case SK_FunctionReferenceConversion:
8350 assert(CurInit.get()->isLValue() &&
8351 "function reference should be lvalue");
8352 CurInit =
8353 S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK_LValue);
8354 break;
8355
8356 case SK_AtomicConversion: {
8357 assert(CurInit.get()->isRValue() && "cannot convert glvalue to atomic");
8358 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8359 CK_NonAtomicToAtomic, VK_RValue);
8360 break;
8361 }
8362
8363 case SK_ConversionSequence:
8364 case SK_ConversionSequenceNoNarrowing: {
8365 if (const auto *FromPtrType =
8366 CurInit.get()->getType()->getAs<PointerType>()) {
8367 if (const auto *ToPtrType = Step->Type->getAs<PointerType>()) {
8368 if (FromPtrType->getPointeeType()->hasAttr(attr::NoDeref) &&
8369 !ToPtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
8370 // Do not check static casts here because they are checked earlier
8371 // in Sema::ActOnCXXNamedCast()
8372 if (!Kind.isStaticCast()) {
8373 S.Diag(CurInit.get()->getExprLoc(),
8374 diag::warn_noderef_to_dereferenceable_pointer)
8375 << CurInit.get()->getSourceRange();
8376 }
8377 }
8378 }
8379 }
8380
8381 Sema::CheckedConversionKind CCK
8382 = Kind.isCStyleCast()? Sema::CCK_CStyleCast
8383 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast
8384 : Kind.isExplicitCast()? Sema::CCK_OtherCast
8385 : Sema::CCK_ImplicitConversion;
8386 ExprResult CurInitExprRes =
8387 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS,
8388 getAssignmentAction(Entity), CCK);
8389 if (CurInitExprRes.isInvalid())
8390 return ExprError();
8391
8392 S.DiscardMisalignedMemberAddress(Step->Type.getTypePtr(), CurInit.get());
8393
8394 CurInit = CurInitExprRes;
8395
8396 if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
8397 S.getLangOpts().CPlusPlus)
8398 DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(),
8399 CurInit.get());
8400
8401 break;
8402 }
8403
8404 case SK_ListInitialization: {
8405 if (checkAbstractType(Step->Type))
8406 return ExprError();
8407
8408 InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
8409 // If we're not initializing the top-level entity, we need to create an
8410 // InitializeTemporary entity for our target type.
8411 QualType Ty = Step->Type;
8412 bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
8413 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
8414 InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
8415 InitListChecker PerformInitList(S, InitEntity,
8416 InitList, Ty, /*VerifyOnly=*/false,
8417 /*TreatUnavailableAsInvalid=*/false);
8418 if (PerformInitList.HadError())
8419 return ExprError();
8420
8421 // Hack: We must update *ResultType if available in order to set the
8422 // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
8423 // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
8424 if (ResultType &&
8425 ResultType->getNonReferenceType()->isIncompleteArrayType()) {
8426 if ((*ResultType)->isRValueReferenceType())
8427 Ty = S.Context.getRValueReferenceType(Ty);
8428 else if ((*ResultType)->isLValueReferenceType())
8429 Ty = S.Context.getLValueReferenceType(Ty,
8430 (*ResultType)->castAs<LValueReferenceType>()->isSpelledAsLValue());
8431 *ResultType = Ty;
8432 }
8433
8434 InitListExpr *StructuredInitList =
8435 PerformInitList.getFullyStructuredList();
8436 CurInit.get();
8437 CurInit = shouldBindAsTemporary(InitEntity)
8438 ? S.MaybeBindToTemporary(StructuredInitList)
8439 : StructuredInitList;
8440 break;
8441 }
8442
8443 case SK_ConstructorInitializationFromList: {
8444 if (checkAbstractType(Step->Type))
8445 return ExprError();
8446
8447 // When an initializer list is passed for a parameter of type "reference
8448 // to object", we don't get an EK_Temporary entity, but instead an
8449 // EK_Parameter entity with reference type.
8450 // FIXME: This is a hack. What we really should do is create a user
8451 // conversion step for this case, but this makes it considerably more
8452 // complicated. For now, this will do.
8453 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
8454 Entity.getType().getNonReferenceType());
8455 bool UseTemporary = Entity.getType()->isReferenceType();
8456 assert(Args.size() == 1 && "expected a single argument for list init");
8457 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
8458 S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init)
8459 << InitList->getSourceRange();
8460 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits());
8461 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity :
8462 Entity,
8463 Kind, Arg, *Step,
8464 ConstructorInitRequiresZeroInit,
8465 /*IsListInitialization*/true,
8466 /*IsStdInitListInit*/false,
8467 InitList->getLBraceLoc(),
8468 InitList->getRBraceLoc());
8469 break;
8470 }
8471
8472 case SK_UnwrapInitList:
8473 CurInit = cast<InitListExpr>(CurInit.get())->getInit(0);
8474 break;
8475
8476 case SK_RewrapInitList: {
8477 Expr *E = CurInit.get();
8478 InitListExpr *Syntactic = Step->WrappingSyntacticList;
8479 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context,
8480 Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc());
8481 ILE->setSyntacticForm(Syntactic);
8482 ILE->setType(E->getType());
8483 ILE->setValueKind(E->getValueKind());
8484 CurInit = ILE;
8485 break;
8486 }
8487
8488 case SK_ConstructorInitialization:
8489 case SK_StdInitializerListConstructorCall: {
8490 if (checkAbstractType(Step->Type))
8491 return ExprError();
8492
8493 // When an initializer list is passed for a parameter of type "reference
8494 // to object", we don't get an EK_Temporary entity, but instead an
8495 // EK_Parameter entity with reference type.
8496 // FIXME: This is a hack. What we really should do is create a user
8497 // conversion step for this case, but this makes it considerably more
8498 // complicated. For now, this will do.
8499 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
8500 Entity.getType().getNonReferenceType());
8501 bool UseTemporary = Entity.getType()->isReferenceType();
8502 bool IsStdInitListInit =
8503 Step->Kind == SK_StdInitializerListConstructorCall;
8504 Expr *Source = CurInit.get();
8505 SourceRange Range = Kind.hasParenOrBraceRange()
8506 ? Kind.getParenOrBraceRange()
8507 : SourceRange();
8508 CurInit = PerformConstructorInitialization(
8509 S, UseTemporary ? TempEntity : Entity, Kind,
8510 Source ? MultiExprArg(Source) : Args, *Step,
8511 ConstructorInitRequiresZeroInit,
8512 /*IsListInitialization*/ IsStdInitListInit,
8513 /*IsStdInitListInitialization*/ IsStdInitListInit,
8514 /*LBraceLoc*/ Range.getBegin(),
8515 /*RBraceLoc*/ Range.getEnd());
8516 break;
8517 }
8518
8519 case SK_ZeroInitialization: {
8520 step_iterator NextStep = Step;
8521 ++NextStep;
8522 if (NextStep != StepEnd &&
8523 (NextStep->Kind == SK_ConstructorInitialization ||
8524 NextStep->Kind == SK_ConstructorInitializationFromList)) {
8525 // The need for zero-initialization is recorded directly into
8526 // the call to the object's constructor within the next step.
8527 ConstructorInitRequiresZeroInit = true;
8528 } else if (Kind.getKind() == InitializationKind::IK_Value &&
8529 S.getLangOpts().CPlusPlus &&
8530 !Kind.isImplicitValueInit()) {
8531 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
8532 if (!TSInfo)
8533 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type,
8534 Kind.getRange().getBegin());
8535
8536 CurInit = new (S.Context) CXXScalarValueInitExpr(
8537 Entity.getType().getNonLValueExprType(S.Context), TSInfo,
8538 Kind.getRange().getEnd());
8539 } else {
8540 CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type);
8541 }
8542 break;
8543 }
8544
8545 case SK_CAssignment: {
8546 QualType SourceType = CurInit.get()->getType();
8547
8548 // Save off the initial CurInit in case we need to emit a diagnostic
8549 ExprResult InitialCurInit = CurInit;
8550 ExprResult Result = CurInit;
8551 Sema::AssignConvertType ConvTy =
8552 S.CheckSingleAssignmentConstraints(Step->Type, Result, true,
8553 Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited);
8554 if (Result.isInvalid())
8555 return ExprError();
8556 CurInit = Result;
8557
8558 // If this is a call, allow conversion to a transparent union.
8559 ExprResult CurInitExprRes = CurInit;
8560 if (ConvTy != Sema::Compatible &&
8561 Entity.isParameterKind() &&
8562 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes)
8563 == Sema::Compatible)
8564 ConvTy = Sema::Compatible;
8565 if (CurInitExprRes.isInvalid())
8566 return ExprError();
8567 CurInit = CurInitExprRes;
8568
8569 bool Complained;
8570 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(),
8571 Step->Type, SourceType,
8572 InitialCurInit.get(),
8573 getAssignmentAction(Entity, true),
8574 &Complained)) {
8575 PrintInitLocationNote(S, Entity);
8576 return ExprError();
8577 } else if (Complained)
8578 PrintInitLocationNote(S, Entity);
8579 break;
8580 }
8581
8582 case SK_StringInit: {
8583 QualType Ty = Step->Type;
8584 bool UpdateType = ResultType && Entity.getType()->isIncompleteArrayType();
8585 CheckStringInit(CurInit.get(), UpdateType ? *ResultType : Ty,
8586 S.Context.getAsArrayType(Ty), S);
8587 break;
8588 }
8589
8590 case SK_ObjCObjectConversion:
8591 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8592 CK_ObjCObjectLValueCast,
8593 CurInit.get()->getValueKind());
8594 break;
8595
8596 case SK_ArrayLoopIndex: {
8597 Expr *Cur = CurInit.get();
8598 Expr *BaseExpr = new (S.Context)
8599 OpaqueValueExpr(Cur->getExprLoc(), Cur->getType(),
8600 Cur->getValueKind(), Cur->getObjectKind(), Cur);
8601 Expr *IndexExpr =
8602 new (S.Context) ArrayInitIndexExpr(S.Context.getSizeType());
8603 CurInit = S.CreateBuiltinArraySubscriptExpr(
8604 BaseExpr, Kind.getLocation(), IndexExpr, Kind.getLocation());
8605 ArrayLoopCommonExprs.push_back(BaseExpr);
8606 break;
8607 }
8608
8609 case SK_ArrayLoopInit: {
8610 assert(!ArrayLoopCommonExprs.empty() &&
8611 "mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit");
8612 Expr *Common = ArrayLoopCommonExprs.pop_back_val();
8613 CurInit = new (S.Context) ArrayInitLoopExpr(Step->Type, Common,
8614 CurInit.get());
8615 break;
8616 }
8617
8618 case SK_GNUArrayInit:
8619 // Okay: we checked everything before creating this step. Note that
8620 // this is a GNU extension.
8621 S.Diag(Kind.getLocation(), diag::ext_array_init_copy)
8622 << Step->Type << CurInit.get()->getType()
8623 << CurInit.get()->getSourceRange();
8624 updateGNUCompoundLiteralRValue(CurInit.get());
8625 LLVM_FALLTHROUGH;
8626 case SK_ArrayInit:
8627 // If the destination type is an incomplete array type, update the
8628 // type accordingly.
8629 if (ResultType) {
8630 if (const IncompleteArrayType *IncompleteDest
8631 = S.Context.getAsIncompleteArrayType(Step->Type)) {
8632 if (const ConstantArrayType *ConstantSource
8633 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) {
8634 *ResultType = S.Context.getConstantArrayType(
8635 IncompleteDest->getElementType(),
8636 ConstantSource->getSize(),
8637 ConstantSource->getSizeExpr(),
8638 ArrayType::Normal, 0);
8639 }
8640 }
8641 }
8642 break;
8643
8644 case SK_ParenthesizedArrayInit:
8645 // Okay: we checked everything before creating this step. Note that
8646 // this is a GNU extension.
8647 S.Diag(Kind.getLocation(), diag::ext_array_init_parens)
8648 << CurInit.get()->getSourceRange();
8649 break;
8650
8651 case SK_PassByIndirectCopyRestore:
8652 case SK_PassByIndirectRestore:
8653 checkIndirectCopyRestoreSource(S, CurInit.get());
8654 CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr(
8655 CurInit.get(), Step->Type,
8656 Step->Kind == SK_PassByIndirectCopyRestore);
8657 break;
8658
8659 case SK_ProduceObjCObject:
8660 CurInit = ImplicitCastExpr::Create(
8661 S.Context, Step->Type, CK_ARCProduceObject, CurInit.get(), nullptr,
8662 VK_RValue, FPOptionsOverride());
8663 break;
8664
8665 case SK_StdInitializerList: {
8666 S.Diag(CurInit.get()->getExprLoc(),
8667 diag::warn_cxx98_compat_initializer_list_init)
8668 << CurInit.get()->getSourceRange();
8669
8670 // Materialize the temporary into memory.
8671 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
8672 CurInit.get()->getType(), CurInit.get(),
8673 /*BoundToLvalueReference=*/false);
8674
8675 // Wrap it in a construction of a std::initializer_list<T>.
8676 CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE);
8677
8678 // Bind the result, in case the library has given initializer_list a
8679 // non-trivial destructor.
8680 if (shouldBindAsTemporary(Entity))
8681 CurInit = S.MaybeBindToTemporary(CurInit.get());
8682 break;
8683 }
8684
8685 case SK_OCLSamplerInit: {
8686 // Sampler initialization have 5 cases:
8687 // 1. function argument passing
8688 // 1a. argument is a file-scope variable
8689 // 1b. argument is a function-scope variable
8690 // 1c. argument is one of caller function's parameters
8691 // 2. variable initialization
8692 // 2a. initializing a file-scope variable
8693 // 2b. initializing a function-scope variable
8694 //
8695 // For file-scope variables, since they cannot be initialized by function
8696 // call of __translate_sampler_initializer in LLVM IR, their references
8697 // need to be replaced by a cast from their literal initializers to
8698 // sampler type. Since sampler variables can only be used in function
8699 // calls as arguments, we only need to replace them when handling the
8700 // argument passing.
8701 assert(Step->Type->isSamplerT() &&
8702 "Sampler initialization on non-sampler type.");
8703 Expr *Init = CurInit.get()->IgnoreParens();
8704 QualType SourceType = Init->getType();
8705 // Case 1
8706 if (Entity.isParameterKind()) {
8707 if (!SourceType->isSamplerT() && !SourceType->isIntegerType()) {
8708 S.Diag(Kind.getLocation(), diag::err_sampler_argument_required)
8709 << SourceType;
8710 break;
8711 } else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init)) {
8712 auto Var = cast<VarDecl>(DRE->getDecl());
8713 // Case 1b and 1c
8714 // No cast from integer to sampler is needed.
8715 if (!Var->hasGlobalStorage()) {
8716 CurInit = ImplicitCastExpr::Create(
8717 S.Context, Step->Type, CK_LValueToRValue, Init,
8718 /*BasePath=*/nullptr, VK_RValue, FPOptionsOverride());
8719 break;
8720 }
8721 // Case 1a
8722 // For function call with a file-scope sampler variable as argument,
8723 // get the integer literal.
8724 // Do not diagnose if the file-scope variable does not have initializer
8725 // since this has already been diagnosed when parsing the variable
8726 // declaration.
8727 if (!Var->getInit() || !isa<ImplicitCastExpr>(Var->getInit()))
8728 break;
8729 Init = cast<ImplicitCastExpr>(const_cast<Expr*>(
8730 Var->getInit()))->getSubExpr();
8731 SourceType = Init->getType();
8732 }
8733 } else {
8734 // Case 2
8735 // Check initializer is 32 bit integer constant.
8736 // If the initializer is taken from global variable, do not diagnose since
8737 // this has already been done when parsing the variable declaration.
8738 if (!Init->isConstantInitializer(S.Context, false))
8739 break;
8740
8741 if (!SourceType->isIntegerType() ||
8742 32 != S.Context.getIntWidth(SourceType)) {
8743 S.Diag(Kind.getLocation(), diag::err_sampler_initializer_not_integer)
8744 << SourceType;
8745 break;
8746 }
8747
8748 Expr::EvalResult EVResult;
8749 Init->EvaluateAsInt(EVResult, S.Context);
8750 llvm::APSInt Result = EVResult.Val.getInt();
8751 const uint64_t SamplerValue = Result.getLimitedValue();
8752 // 32-bit value of sampler's initializer is interpreted as
8753 // bit-field with the following structure:
8754 // |unspecified|Filter|Addressing Mode| Normalized Coords|
8755 // |31 6|5 4|3 1| 0|
8756 // This structure corresponds to enum values of sampler properties
8757 // defined in SPIR spec v1.2 and also opencl-c.h
8758 unsigned AddressingMode = (0x0E & SamplerValue) >> 1;
8759 unsigned FilterMode = (0x30 & SamplerValue) >> 4;
8760 if (FilterMode != 1 && FilterMode != 2 &&
8761 !S.getOpenCLOptions().isEnabled(
8762 "cl_intel_device_side_avc_motion_estimation"))
8763 S.Diag(Kind.getLocation(),
8764 diag::warn_sampler_initializer_invalid_bits)
8765 << "Filter Mode";
8766 if (AddressingMode > 4)
8767 S.Diag(Kind.getLocation(),
8768 diag::warn_sampler_initializer_invalid_bits)
8769 << "Addressing Mode";
8770 }
8771
8772 // Cases 1a, 2a and 2b
8773 // Insert cast from integer to sampler.
8774 CurInit = S.ImpCastExprToType(Init, S.Context.OCLSamplerTy,
8775 CK_IntToOCLSampler);
8776 break;
8777 }
8778 case SK_OCLZeroOpaqueType: {
8779 assert((Step->Type->isEventT() || Step->Type->isQueueT() ||
8780 Step->Type->isOCLIntelSubgroupAVCType()) &&
8781 "Wrong type for initialization of OpenCL opaque type.");
8782
8783 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
8784 CK_ZeroToOCLOpaqueType,
8785 CurInit.get()->getValueKind());
8786 break;
8787 }
8788 }
8789 }
8790
8791 // Check whether the initializer has a shorter lifetime than the initialized
8792 // entity, and if not, either lifetime-extend or warn as appropriate.
8793 if (auto *Init = CurInit.get())
8794 S.checkInitializerLifetime(Entity, Init);
8795
8796 // Diagnose non-fatal problems with the completed initialization.
8797 if (Entity.getKind() == InitializedEntity::EK_Member &&
8798 cast<FieldDecl>(Entity.getDecl())->isBitField())
8799 S.CheckBitFieldInitialization(Kind.getLocation(),
8800 cast<FieldDecl>(Entity.getDecl()),
8801 CurInit.get());
8802
8803 // Check for std::move on construction.
8804 if (const Expr *E = CurInit.get()) {
8805 CheckMoveOnConstruction(S, E,
8806 Entity.getKind() == InitializedEntity::EK_Result);
8807 }
8808
8809 return CurInit;
8810}
8811
8812/// Somewhere within T there is an uninitialized reference subobject.
8813/// Dig it out and diagnose it.
8814static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc,
8815 QualType T) {
8816 if (T->isReferenceType()) {
8817 S.Diag(Loc, diag::err_reference_without_init)
8818 << T.getNonReferenceType();
8819 return true;
8820 }
8821
8822 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
8823 if (!RD || !RD->hasUninitializedReferenceMember())
8824 return false;
8825
8826 for (const auto *FI : RD->fields()) {
8827 if (FI->isUnnamedBitfield())
8828 continue;
8829
8830 if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) {
8831 S.Diag(Loc, diag::note_value_initialization_here) << RD;
8832 return true;
8833 }
8834 }
8835
8836 for (const auto &BI : RD->bases()) {
8837 if (DiagnoseUninitializedReference(S, BI.getBeginLoc(), BI.getType())) {
8838 S.Diag(Loc, diag::note_value_initialization_here) << RD;
8839 return true;
8840 }
8841 }
8842
8843 return false;
8844}
8845
8846
8847//===----------------------------------------------------------------------===//
8848// Diagnose initialization failures
8849//===----------------------------------------------------------------------===//
8850
8851/// Emit notes associated with an initialization that failed due to a
8852/// "simple" conversion failure.
8853static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity,
8854 Expr *op) {
8855 QualType destType = entity.getType();
8856 if (destType.getNonReferenceType()->isObjCObjectPointerType() &&
8857 op->getType()->isObjCObjectPointerType()) {
8858
8859 // Emit a possible note about the conversion failing because the
8860 // operand is a message send with a related result type.
8861 S.EmitRelatedResultTypeNote(op);
8862
8863 // Emit a possible note about a return failing because we're
8864 // expecting a related result type.
8865 if (entity.getKind() == InitializedEntity::EK_Result)
8866 S.EmitRelatedResultTypeNoteForReturn(destType);
8867 }
8868 QualType fromType = op->getType();
8869 auto *fromDecl = fromType.getTypePtr()->getPointeeCXXRecordDecl();
8870 auto *destDecl = destType.getTypePtr()->getPointeeCXXRecordDecl();
8871 if (fromDecl && destDecl && fromDecl->getDeclKind() == Decl::CXXRecord &&
8872 destDecl->getDeclKind() == Decl::CXXRecord &&
8873 !fromDecl->isInvalidDecl() && !destDecl->isInvalidDecl() &&
8874 !fromDecl->hasDefinition())
8875 S.Diag(fromDecl->getLocation(), diag::note_forward_class_conversion)
8876 << S.getASTContext().getTagDeclType(fromDecl)
8877 << S.getASTContext().getTagDeclType(destDecl);
8878}
8879
8880static void diagnoseListInit(Sema &S, const InitializedEntity &Entity,
8881 InitListExpr *InitList) {
8882 QualType DestType = Entity.getType();
8883
8884 QualType E;
8885 if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) {
8886 QualType ArrayType = S.Context.getConstantArrayType(
8887 E.withConst(),
8888 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
8889 InitList->getNumInits()),
8890 nullptr, clang::ArrayType::Normal, 0);
8891 InitializedEntity HiddenArray =
8892 InitializedEntity::InitializeTemporary(ArrayType);
8893 return diagnoseListInit(S, HiddenArray, InitList);
8894 }
8895
8896 if (DestType->isReferenceType()) {
8897 // A list-initialization failure for a reference means that we tried to
8898 // create a temporary of the inner type (per [dcl.init.list]p3.6) and the
8899 // inner initialization failed.
8900 QualType T = DestType->castAs<ReferenceType>()->getPointeeType();
8901 diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList);
8902 SourceLocation Loc = InitList->getBeginLoc();
8903 if (auto *D = Entity.getDecl())
8904 Loc = D->getLocation();
8905 S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T;
8906 return;
8907 }
8908
8909 InitListChecker DiagnoseInitList(S, Entity, InitList, DestType,
8910 /*VerifyOnly=*/false,
8911 /*TreatUnavailableAsInvalid=*/false);
8912 assert(DiagnoseInitList.HadError() &&
8913 "Inconsistent init list check result.");
8914}
8915
8916bool InitializationSequence::Diagnose(Sema &S,
8917 const InitializedEntity &Entity,
8918 const InitializationKind &Kind,
8919 ArrayRef<Expr *> Args) {
8920 if (!Failed())
8921 return false;
8922
8923 // When we want to diagnose only one element of a braced-init-list,
8924 // we need to factor it out.
8925 Expr *OnlyArg;
8926 if (Args.size() == 1) {
8927 auto *List = dyn_cast<InitListExpr>(Args[0]);
8928 if (List && List->getNumInits() == 1)
8929 OnlyArg = List->getInit(0);
8930 else
8931 OnlyArg = Args[0];
8932 }
8933 else
8934 OnlyArg = nullptr;
8935
8936 QualType DestType = Entity.getType();
8937 switch (Failure) {
8938 case FK_TooManyInitsForReference:
8939 // FIXME: Customize for the initialized entity?
8940 if (Args.empty()) {
8941 // Dig out the reference subobject which is uninitialized and diagnose it.
8942 // If this is value-initialization, this could be nested some way within
8943 // the target type.
8944 assert(Kind.getKind() == InitializationKind::IK_Value ||
8945 DestType->isReferenceType());
8946 bool Diagnosed =
8947 DiagnoseUninitializedReference(S, Kind.getLocation(), DestType);
8948 assert(Diagnosed && "couldn't find uninitialized reference to diagnose");
8949 (void)Diagnosed;
8950 } else // FIXME: diagnostic below could be better!
8951 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
8952 << SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());
8953 break;
8954 case FK_ParenthesizedListInitForReference:
8955 S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
8956 << 1 << Entity.getType() << Args[0]->getSourceRange();
8957 break;
8958
8959 case FK_ArrayNeedsInitList:
8960 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0;
8961 break;
8962 case FK_ArrayNeedsInitListOrStringLiteral:
8963 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1;
8964 break;
8965 case FK_ArrayNeedsInitListOrWideStringLiteral:
8966 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2;
8967 break;
8968 case FK_NarrowStringIntoWideCharArray:
8969 S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar);
8970 break;
8971 case FK_WideStringIntoCharArray:
8972 S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char);
8973 break;
8974 case FK_IncompatWideStringIntoWideChar:
8975 S.Diag(Kind.getLocation(),
8976 diag::err_array_init_incompat_wide_string_into_wchar);
8977 break;
8978 case FK_PlainStringIntoUTF8Char:
8979 S.Diag(Kind.getLocation(),
8980 diag::err_array_init_plain_string_into_char8_t);
8981 S.Diag(Args.front()->getBeginLoc(),
8982 diag::note_array_init_plain_string_into_char8_t)
8983 << FixItHint::CreateInsertion(Args.front()->getBeginLoc(), "u8");
8984 break;
8985 case FK_UTF8StringIntoPlainChar:
8986 S.Diag(Kind.getLocation(),
8987 diag::err_array_init_utf8_string_into_char)
8988 << S.getLangOpts().CPlusPlus20;
8989 break;
8990 case FK_ArrayTypeMismatch:
8991 case FK_NonConstantArrayInit:
8992 S.Diag(Kind.getLocation(),
8993 (Failure == FK_ArrayTypeMismatch
8994 ? diag::err_array_init_different_type
8995 : diag::err_array_init_non_constant_array))
8996 << DestType.getNonReferenceType()
8997 << OnlyArg->getType()
8998 << Args[0]->getSourceRange();
8999 break;
9000
9001 case FK_VariableLengthArrayHasInitializer:
9002 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init)
9003 << Args[0]->getSourceRange();
9004 break;
9005
9006 case FK_AddressOfOverloadFailed: {
9007 DeclAccessPair Found;
9008 S.ResolveAddressOfOverloadedFunction(OnlyArg,
9009 DestType.getNonReferenceType(),
9010 true,
9011 Found);
9012 break;
9013 }
9014
9015 case FK_AddressOfUnaddressableFunction: {
9016 auto *FD = cast<FunctionDecl>(cast<DeclRefExpr>(OnlyArg)->getDecl());
9017 S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
9018 OnlyArg->getBeginLoc());
9019 break;
9020 }
9021
9022 case FK_ReferenceInitOverloadFailed:
9023 case FK_UserConversionOverloadFailed:
9024 switch (FailedOverloadResult) {
9025 case OR_Ambiguous:
9026
9027 FailedCandidateSet.NoteCandidates(
9028 PartialDiagnosticAt(
9029 Kind.getLocation(),
9030 Failure == FK_UserConversionOverloadFailed
9031 ? (S.PDiag(diag::err_typecheck_ambiguous_condition)
9032 << OnlyArg->getType() << DestType
9033 << Args[0]->getSourceRange())
9034 : (S.PDiag(diag::err_ref_init_ambiguous)
9035 << DestType << OnlyArg->getType()
9036 << Args[0]->getSourceRange())),
9037 S, OCD_AmbiguousCandidates, Args);
9038 break;
9039
9040 case OR_No_Viable_Function: {
9041 auto Cands = FailedCandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args);
9042 if (!S.RequireCompleteType(Kind.getLocation(),
9043 DestType.getNonReferenceType(),
9044 diag::err_typecheck_nonviable_condition_incomplete,
9045 OnlyArg->getType(), Args[0]->getSourceRange()))
9046 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
9047 << (Entity.getKind() == InitializedEntity::EK_Result)
9048 << OnlyArg->getType() << Args[0]->getSourceRange()
9049 << DestType.getNonReferenceType();
9050
9051 FailedCandidateSet.NoteCandidates(S, Args, Cands);
9052 break;
9053 }
9054 case OR_Deleted: {
9055 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
9056 << OnlyArg->getType() << DestType.getNonReferenceType()
9057 << Args[0]->getSourceRange();
9058 OverloadCandidateSet::iterator Best;
9059 OverloadingResult Ovl
9060 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9061 if (Ovl == OR_Deleted) {
9062 S.NoteDeletedFunction(Best->Function);
9063 } else {
9064 llvm_unreachable("Inconsistent overload resolution?");
9065 }
9066 break;
9067 }
9068
9069 case OR_Success:
9070 llvm_unreachable("Conversion did not fail!");
9071 }
9072 break;
9073
9074 case FK_NonConstLValueReferenceBindingToTemporary:
9075 if (isa<InitListExpr>(Args[0])) {
9076 S.Diag(Kind.getLocation(),
9077 diag::err_lvalue_reference_bind_to_initlist)
9078 << DestType.getNonReferenceType().isVolatileQualified()
9079 << DestType.getNonReferenceType()
9080 << Args[0]->getSourceRange();
9081 break;
9082 }
9083 LLVM_FALLTHROUGH;
9084
9085 case FK_NonConstLValueReferenceBindingToUnrelated:
9086 S.Diag(Kind.getLocation(),
9087 Failure == FK_NonConstLValueReferenceBindingToTemporary
9088 ? diag::err_lvalue_reference_bind_to_temporary
9089 : diag::err_lvalue_reference_bind_to_unrelated)
9090 << DestType.getNonReferenceType().isVolatileQualified()
9091 << DestType.getNonReferenceType()
9092 << OnlyArg->getType()
9093 << Args[0]->getSourceRange();
9094 break;
9095
9096 case FK_NonConstLValueReferenceBindingToBitfield: {
9097 // We don't necessarily have an unambiguous source bit-field.
9098 FieldDecl *BitField = Args[0]->getSourceBitField();
9099 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
9100 << DestType.isVolatileQualified()
9101 << (BitField ? BitField->getDeclName() : DeclarationName())
9102 << (BitField != nullptr)
9103 << Args[0]->getSourceRange();
9104 if (BitField)
9105 S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
9106 break;
9107 }
9108
9109 case FK_NonConstLValueReferenceBindingToVectorElement:
9110 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element)
9111 << DestType.isVolatileQualified()
9112 << Args[0]->getSourceRange();
9113 break;
9114
9115 case FK_NonConstLValueReferenceBindingToMatrixElement:
9116 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_matrix_element)
9117 << DestType.isVolatileQualified() << Args[0]->getSourceRange();
9118 break;
9119
9120 case FK_RValueReferenceBindingToLValue:
9121 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
9122 << DestType.getNonReferenceType() << OnlyArg->getType()
9123 << Args[0]->getSourceRange();
9124 break;
9125
9126 case FK_ReferenceAddrspaceMismatchTemporary:
9127 S.Diag(Kind.getLocation(), diag::err_reference_bind_temporary_addrspace)
9128 << DestType << Args[0]->getSourceRange();
9129 break;
9130
9131 case FK_ReferenceInitDropsQualifiers: {
9132 QualType SourceType = OnlyArg->getType();
9133 QualType NonRefType = DestType.getNonReferenceType();
9134 Qualifiers DroppedQualifiers =
9135 SourceType.getQualifiers() - NonRefType.getQualifiers();
9136
9137 if (!NonRefType.getQualifiers().isAddressSpaceSupersetOf(
9138 SourceType.getQualifiers()))
9139 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9140 << NonRefType << SourceType << 1 /*addr space*/
9141 << Args[0]->getSourceRange();
9142 else if (DroppedQualifiers.hasQualifiers())
9143 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9144 << NonRefType << SourceType << 0 /*cv quals*/
9145 << Qualifiers::fromCVRMask(DroppedQualifiers.getCVRQualifiers())
9146 << DroppedQualifiers.getCVRQualifiers() << Args[0]->getSourceRange();
9147 else
9148 // FIXME: Consider decomposing the type and explaining which qualifiers
9149 // were dropped where, or on which level a 'const' is missing, etc.
9150 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
9151 << NonRefType << SourceType << 2 /*incompatible quals*/
9152 << Args[0]->getSourceRange();
9153 break;
9154 }
9155
9156 case FK_ReferenceInitFailed:
9157 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
9158 << DestType.getNonReferenceType()
9159 << DestType.getNonReferenceType()->isIncompleteType()
9160 << OnlyArg->isLValue()
9161 << OnlyArg->getType()
9162 << Args[0]->getSourceRange();
9163 emitBadConversionNotes(S, Entity, Args[0]);
9164 break;
9165
9166 case FK_ConversionFailed: {
9167 QualType FromType = OnlyArg->getType();
9168 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed)
9169 << (int)Entity.getKind()
9170 << DestType
9171 << OnlyArg->isLValue()
9172 << FromType
9173 << Args[0]->getSourceRange();
9174 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType);
9175 S.Diag(Kind.getLocation(), PDiag);
9176 emitBadConversionNotes(S, Entity, Args[0]);
9177 break;
9178 }
9179
9180 case FK_ConversionFromPropertyFailed:
9181 // No-op. This error has already been reported.
9182 break;
9183
9184 case FK_TooManyInitsForScalar: {
9185 SourceRange R;
9186
9187 auto *InitList = dyn_cast<InitListExpr>(Args[0]);
9188 if (InitList && InitList->getNumInits() >= 1) {
9189 R = SourceRange(InitList->getInit(0)->getEndLoc(), InitList->getEndLoc());
9190 } else {
9191 assert(Args.size() > 1 && "Expected multiple initializers!");
9192 R = SourceRange(Args.front()->getEndLoc(), Args.back()->getEndLoc());
9193 }
9194
9195 R.setBegin(S.getLocForEndOfToken(R.getBegin()));
9196 if (Kind.isCStyleOrFunctionalCast())
9197 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg)
9198 << R;
9199 else
9200 S.Diag(Kind.getLocation(), diag::err_excess_initializers)
9201 << /*scalar=*/2 << R;
9202 break;
9203 }
9204
9205 case FK_ParenthesizedListInitForScalar:
9206 S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
9207 << 0 << Entity.getType() << Args[0]->getSourceRange();
9208 break;
9209
9210 case FK_ReferenceBindingToInitList:
9211 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
9212 << DestType.getNonReferenceType() << Args[0]->getSourceRange();
9213 break;
9214
9215 case FK_InitListBadDestinationType:
9216 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
9217 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
9218 break;
9219
9220 case FK_ListConstructorOverloadFailed:
9221 case FK_ConstructorOverloadFailed: {
9222 SourceRange ArgsRange;
9223 if (Args.size())
9224 ArgsRange =
9225 SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());
9226
9227 if (Failure == FK_ListConstructorOverloadFailed) {
9228 assert(Args.size() == 1 &&
9229 "List construction from other than 1 argument.");
9230 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
9231 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
9232 }
9233
9234 // FIXME: Using "DestType" for the entity we're printing is probably
9235 // bad.
9236 switch (FailedOverloadResult) {
9237 case OR_Ambiguous:
9238 FailedCandidateSet.NoteCandidates(
9239 PartialDiagnosticAt(Kind.getLocation(),
9240 S.PDiag(diag::err_ovl_ambiguous_init)
9241 << DestType << ArgsRange),
9242 S, OCD_AmbiguousCandidates, Args);
9243 break;
9244
9245 case OR_No_Viable_Function:
9246 if (Kind.getKind() == InitializationKind::IK_Default &&
9247 (Entity.getKind() == InitializedEntity::EK_Base ||
9248 Entity.getKind() == InitializedEntity::EK_Member) &&
9249 isa<CXXConstructorDecl>(S.CurContext)) {
9250 // This is implicit default initialization of a member or
9251 // base within a constructor. If no viable function was
9252 // found, notify the user that they need to explicitly
9253 // initialize this base/member.
9254 CXXConstructorDecl *Constructor
9255 = cast<CXXConstructorDecl>(S.CurContext);
9256 const CXXRecordDecl *InheritedFrom = nullptr;
9257 if (auto Inherited = Constructor->getInheritedConstructor())
9258 InheritedFrom = Inherited.getShadowDecl()->getNominatedBaseClass();
9259 if (Entity.getKind() == InitializedEntity::EK_Base) {
9260 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
9261 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
9262 << S.Context.getTypeDeclType(Constructor->getParent())
9263 << /*base=*/0
9264 << Entity.getType()
9265 << InheritedFrom;
9266
9267 RecordDecl *BaseDecl
9268 = Entity.getBaseSpecifier()->getType()->castAs<RecordType>()
9269 ->getDecl();
9270 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl)
9271 << S.Context.getTagDeclType(BaseDecl);
9272 } else {
9273 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
9274 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
9275 << S.Context.getTypeDeclType(Constructor->getParent())
9276 << /*member=*/1
9277 << Entity.getName()
9278 << InheritedFrom;
9279 S.Diag(Entity.getDecl()->getLocation(),
9280 diag::note_member_declared_at);
9281
9282 if (const RecordType *Record
9283 = Entity.getType()->getAs<RecordType>())
9284 S.Diag(Record->getDecl()->getLocation(),
9285 diag::note_previous_decl)
9286 << S.Context.getTagDeclType(Record->getDecl());
9287 }
9288 break;
9289 }
9290
9291 FailedCandidateSet.NoteCandidates(
9292 PartialDiagnosticAt(
9293 Kind.getLocation(),
9294 S.PDiag(diag::err_ovl_no_viable_function_in_init)
9295 << DestType << ArgsRange),
9296 S, OCD_AllCandidates, Args);
9297 break;
9298
9299 case OR_Deleted: {
9300 OverloadCandidateSet::iterator Best;
9301 OverloadingResult Ovl
9302 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9303 if (Ovl != OR_Deleted) {
9304 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
9305 << DestType << ArgsRange;
9306 llvm_unreachable("Inconsistent overload resolution?");
9307 break;
9308 }
9309
9310 // If this is a defaulted or implicitly-declared function, then
9311 // it was implicitly deleted. Make it clear that the deletion was
9312 // implicit.
9313 if (S.isImplicitlyDeleted(Best->Function))
9314 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init)
9315 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function))
9316 << DestType << ArgsRange;
9317 else
9318 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
9319 << DestType << ArgsRange;
9320
9321 S.NoteDeletedFunction(Best->Function);
9322 break;
9323 }
9324
9325 case OR_Success:
9326 llvm_unreachable("Conversion did not fail!");
9327 }
9328 }
9329 break;
9330
9331 case FK_DefaultInitOfConst:
9332 if (Entity.getKind() == InitializedEntity::EK_Member &&
9333 isa<CXXConstructorDecl>(S.CurContext)) {
9334 // This is implicit default-initialization of a const member in
9335 // a constructor. Complain that it needs to be explicitly
9336 // initialized.
9337 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext);
9338 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor)
9339 << (Constructor->getInheritedConstructor() ? 2 :
9340 Constructor->isImplicit() ? 1 : 0)
9341 << S.Context.getTypeDeclType(Constructor->getParent())
9342 << /*const=*/1
9343 << Entity.getName();
9344 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl)
9345 << Entity.getName();
9346 } else {
9347 S.Diag(Kind.getLocation(), diag::err_default_init_const)
9348 << DestType << (bool)DestType->getAs<RecordType>();
9349 }
9350 break;
9351
9352 case FK_Incomplete:
9353 S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType,
9354 diag::err_init_incomplete_type);
9355 break;
9356
9357 case FK_ListInitializationFailed: {
9358 // Run the init list checker again to emit diagnostics.
9359 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
9360 diagnoseListInit(S, Entity, InitList);
9361 break;
9362 }
9363
9364 case FK_PlaceholderType: {
9365 // FIXME: Already diagnosed!
9366 break;
9367 }
9368
9369 case FK_ExplicitConstructor: {
9370 S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor)
9371 << Args[0]->getSourceRange();
9372 OverloadCandidateSet::iterator Best;
9373 OverloadingResult Ovl
9374 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
9375 (void)Ovl;
9376 assert(Ovl == OR_Success && "Inconsistent overload resolution");
9377 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
9378 S.Diag(CtorDecl->getLocation(),
9379 diag::note_explicit_ctor_deduction_guide_here) << false;
9380 break;
9381 }
9382 }
9383
9384 PrintInitLocationNote(S, Entity);
9385 return true;
9386}
9387
9388void InitializationSequence::dump(raw_ostream &OS) const {
9389 switch (SequenceKind) {
9390 case FailedSequence: {
9391 OS << "Failed sequence: ";
9392 switch (Failure) {
9393 case FK_TooManyInitsForReference:
9394 OS << "too many initializers for reference";
9395 break;
9396
9397 case FK_ParenthesizedListInitForReference:
9398 OS << "parenthesized list init for reference";
9399 break;
9400
9401 case FK_ArrayNeedsInitList:
9402 OS << "array requires initializer list";
9403 break;
9404
9405 case FK_AddressOfUnaddressableFunction:
9406 OS << "address of unaddressable function was taken";
9407 break;
9408
9409 case FK_ArrayNeedsInitListOrStringLiteral:
9410 OS << "array requires initializer list or string literal";
9411 break;
9412
9413 case FK_ArrayNeedsInitListOrWideStringLiteral:
9414 OS << "array requires initializer list or wide string literal";
9415 break;
9416
9417 case FK_NarrowStringIntoWideCharArray:
9418 OS << "narrow string into wide char array";
9419 break;
9420
9421 case FK_WideStringIntoCharArray:
9422 OS << "wide string into char array";
9423 break;
9424
9425 case FK_IncompatWideStringIntoWideChar:
9426 OS << "incompatible wide string into wide char array";
9427 break;
9428
9429 case FK_PlainStringIntoUTF8Char:
9430 OS << "plain string literal into char8_t array";
9431 break;
9432
9433 case FK_UTF8StringIntoPlainChar:
9434 OS << "u8 string literal into char array";
9435 break;
9436
9437 case FK_ArrayTypeMismatch:
9438 OS << "array type mismatch";
9439 break;
9440
9441 case FK_NonConstantArrayInit:
9442 OS << "non-constant array initializer";
9443 break;
9444
9445 case FK_AddressOfOverloadFailed:
9446 OS << "address of overloaded function failed";
9447 break;
9448
9449 case FK_ReferenceInitOverloadFailed:
9450 OS << "overload resolution for reference initialization failed";
9451 break;
9452
9453 case FK_NonConstLValueReferenceBindingToTemporary:
9454 OS << "non-const lvalue reference bound to temporary";
9455 break;
9456
9457 case FK_NonConstLValueReferenceBindingToBitfield:
9458 OS << "non-const lvalue reference bound to bit-field";
9459 break;
9460
9461 case FK_NonConstLValueReferenceBindingToVectorElement:
9462 OS << "non-const lvalue reference bound to vector element";
9463 break;
9464
9465 case FK_NonConstLValueReferenceBindingToMatrixElement:
9466 OS << "non-const lvalue reference bound to matrix element";
9467 break;
9468
9469 case FK_NonConstLValueReferenceBindingToUnrelated:
9470 OS << "non-const lvalue reference bound to unrelated type";
9471 break;
9472
9473 case FK_RValueReferenceBindingToLValue:
9474 OS << "rvalue reference bound to an lvalue";
9475 break;
9476
9477 case FK_ReferenceInitDropsQualifiers:
9478 OS << "reference initialization drops qualifiers";
9479 break;
9480
9481 case FK_ReferenceAddrspaceMismatchTemporary:
9482 OS << "reference with mismatching address space bound to temporary";
9483 break;
9484
9485 case FK_ReferenceInitFailed:
9486 OS << "reference initialization failed";
9487 break;
9488
9489 case FK_ConversionFailed:
9490 OS << "conversion failed";
9491 break;
9492
9493 case FK_ConversionFromPropertyFailed:
9494 OS << "conversion from property failed";
9495 break;
9496
9497 case FK_TooManyInitsForScalar:
9498 OS << "too many initializers for scalar";
9499 break;
9500
9501 case FK_ParenthesizedListInitForScalar:
9502 OS << "parenthesized list init for reference";
9503 break;
9504
9505 case FK_ReferenceBindingToInitList:
9506 OS << "referencing binding to initializer list";
9507 break;
9508
9509 case FK_InitListBadDestinationType:
9510 OS << "initializer list for non-aggregate, non-scalar type";
9511 break;
9512
9513 case FK_UserConversionOverloadFailed:
9514 OS << "overloading failed for user-defined conversion";
9515 break;
9516
9517 case FK_ConstructorOverloadFailed:
9518 OS << "constructor overloading failed";
9519 break;
9520
9521 case FK_DefaultInitOfConst:
9522 OS << "default initialization of a const variable";
9523 break;
9524
9525 case FK_Incomplete:
9526 OS << "initialization of incomplete type";
9527 break;
9528
9529 case FK_ListInitializationFailed:
9530 OS << "list initialization checker failure";
9531 break;
9532
9533 case FK_VariableLengthArrayHasInitializer:
9534 OS << "variable length array has an initializer";
9535 break;
9536
9537 case FK_PlaceholderType:
9538 OS << "initializer expression isn't contextually valid";
9539 break;
9540
9541 case FK_ListConstructorOverloadFailed:
9542 OS << "list constructor overloading failed";
9543 break;
9544
9545 case FK_ExplicitConstructor:
9546 OS << "list copy initialization chose explicit constructor";
9547 break;
9548 }
9549 OS << '\n';
9550 return;
9551 }
9552
9553 case DependentSequence:
9554 OS << "Dependent sequence\n";
9555 return;
9556
9557 case NormalSequence:
9558 OS << "Normal sequence: ";
9559 break;
9560 }
9561
9562 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) {
9563 if (S != step_begin()) {
9564 OS << " -> ";
9565 }
9566
9567 switch (S->Kind) {
9568 case SK_ResolveAddressOfOverloadedFunction:
9569 OS << "resolve address of overloaded function";
9570 break;
9571
9572 case SK_CastDerivedToBaseRValue:
9573 OS << "derived-to-base (rvalue)";
9574 break;
9575
9576 case SK_CastDerivedToBaseXValue:
9577 OS << "derived-to-base (xvalue)";
9578 break;
9579
9580 case SK_CastDerivedToBaseLValue:
9581 OS << "derived-to-base (lvalue)";
9582 break;
9583
9584 case SK_BindReference:
9585 OS << "bind reference to lvalue";
9586 break;
9587
9588 case SK_BindReferenceToTemporary:
9589 OS << "bind reference to a temporary";
9590 break;
9591
9592 case SK_FinalCopy:
9593 OS << "final copy in class direct-initialization";
9594 break;
9595
9596 case SK_ExtraneousCopyToTemporary:
9597 OS << "extraneous C++03 copy to temporary";
9598 break;
9599
9600 case SK_UserConversion:
9601 OS << "user-defined conversion via " << *S->Function.Function;
9602 break;
9603
9604 case SK_QualificationConversionRValue:
9605 OS << "qualification conversion (rvalue)";
9606 break;
9607
9608 case SK_QualificationConversionXValue:
9609 OS << "qualification conversion (xvalue)";
9610 break;
9611
9612 case SK_QualificationConversionLValue:
9613 OS << "qualification conversion (lvalue)";
9614 break;
9615
9616 case SK_FunctionReferenceConversion:
9617 OS << "function reference conversion";
9618 break;
9619
9620 case SK_AtomicConversion:
9621 OS << "non-atomic-to-atomic conversion";
9622 break;
9623
9624 case SK_ConversionSequence:
9625 OS << "implicit conversion sequence (";
9626 S->ICS->dump(); // FIXME: use OS
9627 OS << ")";
9628 break;
9629
9630 case SK_ConversionSequenceNoNarrowing:
9631 OS << "implicit conversion sequence with narrowing prohibited (";
9632 S->ICS->dump(); // FIXME: use OS
9633 OS << ")";
9634 break;
9635
9636 case SK_ListInitialization:
9637 OS << "list aggregate initialization";
9638 break;
9639
9640 case SK_UnwrapInitList:
9641 OS << "unwrap reference initializer list";
9642 break;
9643
9644 case SK_RewrapInitList:
9645 OS << "rewrap reference initializer list";
9646 break;
9647
9648 case SK_ConstructorInitialization:
9649 OS << "constructor initialization";
9650 break;
9651
9652 case SK_ConstructorInitializationFromList:
9653 OS << "list initialization via constructor";
9654 break;
9655
9656 case SK_ZeroInitialization:
9657 OS << "zero initialization";
9658 break;
9659
9660 case SK_CAssignment:
9661 OS << "C assignment";
9662 break;
9663
9664 case SK_StringInit:
9665 OS << "string initialization";
9666 break;
9667
9668 case SK_ObjCObjectConversion:
9669 OS << "Objective-C object conversion";
9670 break;
9671
9672 case SK_ArrayLoopIndex:
9673 OS << "indexing for array initialization loop";
9674 break;
9675
9676 case SK_ArrayLoopInit:
9677 OS << "array initialization loop";
9678 break;
9679
9680 case SK_ArrayInit:
9681 OS << "array initialization";
9682 break;
9683
9684 case SK_GNUArrayInit:
9685 OS << "array initialization (GNU extension)";
9686 break;
9687
9688 case SK_ParenthesizedArrayInit:
9689 OS << "parenthesized array initialization";
9690 break;
9691
9692 case SK_PassByIndirectCopyRestore:
9693 OS << "pass by indirect copy and restore";
9694 break;
9695
9696 case SK_PassByIndirectRestore:
9697 OS << "pass by indirect restore";
9698 break;
9699
9700 case SK_ProduceObjCObject:
9701 OS << "Objective-C object retension";
9702 break;
9703
9704 case SK_StdInitializerList:
9705 OS << "std::initializer_list from initializer list";
9706 break;
9707
9708 case SK_StdInitializerListConstructorCall:
9709 OS << "list initialization from std::initializer_list";
9710 break;
9711
9712 case SK_OCLSamplerInit:
9713 OS << "OpenCL sampler_t from integer constant";
9714 break;
9715
9716 case SK_OCLZeroOpaqueType:
9717 OS << "OpenCL opaque type from zero";
9718 break;
9719 }
9720
9721 OS << " [" << S->Type.getAsString() << ']';
9722 }
9723
9724 OS << '\n';
9725}
9726
9727void InitializationSequence::dump() const {
9728 dump(llvm::errs());
9729}
9730
9731static bool NarrowingErrs(const LangOptions &L) {
9732 return L.CPlusPlus11 &&
9733 (!L.MicrosoftExt || L.isCompatibleWithMSVC(LangOptions::MSVC2015));
9734}
9735
9736static void DiagnoseNarrowingInInitList(Sema &S,
9737 const ImplicitConversionSequence &ICS,
9738 QualType PreNarrowingType,
9739 QualType EntityType,
9740 const Expr *PostInit) {
9741 const StandardConversionSequence *SCS = nullptr;
9742 switch (ICS.getKind()) {
9743 case ImplicitConversionSequence::StandardConversion:
9744 SCS = &ICS.Standard;
9745 break;
9746 case ImplicitConversionSequence::UserDefinedConversion:
9747 SCS = &ICS.UserDefined.After;
9748 break;
9749 case ImplicitConversionSequence::AmbiguousConversion:
9750 case ImplicitConversionSequence::EllipsisConversion:
9751 case ImplicitConversionSequence::BadConversion:
9752 return;
9753 }
9754
9755 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion.
9756 APValue ConstantValue;
9757 QualType ConstantType;
9758 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue,
9759 ConstantType)) {
9760 case NK_Not_Narrowing:
9761 case NK_Dependent_Narrowing:
9762 // No narrowing occurred.
9763 return;
9764
9765 case NK_Type_Narrowing:
9766 // This was a floating-to-integer conversion, which is always considered a
9767 // narrowing conversion even if the value is a constant and can be
9768 // represented exactly as an integer.
9769 S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts())
9770 ? diag::ext_init_list_type_narrowing
9771 : diag::warn_init_list_type_narrowing)
9772 << PostInit->getSourceRange()
9773 << PreNarrowingType.getLocalUnqualifiedType()
9774 << EntityType.getLocalUnqualifiedType();
9775 break;
9776
9777 case NK_Constant_Narrowing:
9778 // A constant value was narrowed.
9779 S.Diag(PostInit->getBeginLoc(),
9780 NarrowingErrs(S.getLangOpts())
9781 ? diag::ext_init_list_constant_narrowing
9782 : diag::warn_init_list_constant_narrowing)
9783 << PostInit->getSourceRange()
9784 << ConstantValue.getAsString(S.getASTContext(), ConstantType)
9785 << EntityType.getLocalUnqualifiedType();
9786 break;
9787
9788 case NK_Variable_Narrowing:
9789 // A variable's value may have been narrowed.
9790 S.Diag(PostInit->getBeginLoc(),
9791 NarrowingErrs(S.getLangOpts())
9792 ? diag::ext_init_list_variable_narrowing
9793 : diag::warn_init_list_variable_narrowing)
9794 << PostInit->getSourceRange()
9795 << PreNarrowingType.getLocalUnqualifiedType()
9796 << EntityType.getLocalUnqualifiedType();
9797 break;
9798 }
9799
9800 SmallString<128> StaticCast;
9801 llvm::raw_svector_ostream OS(StaticCast);
9802 OS << "static_cast<";
9803 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) {
9804 // It's important to use the typedef's name if there is one so that the
9805 // fixit doesn't break code using types like int64_t.
9806 //
9807 // FIXME: This will break if the typedef requires qualification. But
9808 // getQualifiedNameAsString() includes non-machine-parsable components.
9809 OS << *TT->getDecl();
9810 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>())
9811 OS << BT->getName(S.getLangOpts());
9812 else {
9813 // Oops, we didn't find the actual type of the variable. Don't emit a fixit
9814 // with a broken cast.
9815 return;
9816 }
9817 OS << ">(";
9818 S.Diag(PostInit->getBeginLoc(), diag::note_init_list_narrowing_silence)
9819 << PostInit->getSourceRange()
9820 << FixItHint::CreateInsertion(PostInit->getBeginLoc(), OS.str())
9821 << FixItHint::CreateInsertion(
9822 S.getLocForEndOfToken(PostInit->getEndLoc()), ")");
9823}
9824
9825//===----------------------------------------------------------------------===//
9826// Initialization helper functions
9827//===----------------------------------------------------------------------===//
9828bool
9829Sema::CanPerformCopyInitialization(const InitializedEntity &Entity,
9830 ExprResult Init) {
9831 if (Init.isInvalid())
9832 return false;
9833
9834 Expr *InitE = Init.get();
9835 assert(InitE && "No initialization expression");
9836
9837 InitializationKind Kind =
9838 InitializationKind::CreateCopy(InitE->getBeginLoc(), SourceLocation());
9839 InitializationSequence Seq(*this, Entity, Kind, InitE);
9840 return !Seq.Failed();
9841}
9842
9843ExprResult
9844Sema::PerformCopyInitialization(const InitializedEntity &Entity,
9845 SourceLocation EqualLoc,
9846 ExprResult Init,
9847 bool TopLevelOfInitList,
9848 bool AllowExplicit) {
9849 if (Init.isInvalid())
9850 return ExprError();
9851
9852 Expr *InitE = Init.get();
9853 assert(InitE && "No initialization expression?");
9854
9855 if (EqualLoc.isInvalid())
9856 EqualLoc = InitE->getBeginLoc();
9857
9858 InitializationKind Kind = InitializationKind::CreateCopy(
9859 InitE->getBeginLoc(), EqualLoc, AllowExplicit);
9860 InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList);
9861
9862 // Prevent infinite recursion when performing parameter copy-initialization.
9863 const bool ShouldTrackCopy =
9864 Entity.isParameterKind() && Seq.isConstructorInitialization();
9865 if (ShouldTrackCopy) {
9866 if (llvm::find(CurrentParameterCopyTypes, Entity.getType()) !=
9867 CurrentParameterCopyTypes.end()) {
9868 Seq.SetOverloadFailure(
9869 InitializationSequence::FK_ConstructorOverloadFailed,
9870 OR_No_Viable_Function);
9871
9872 // Try to give a meaningful diagnostic note for the problematic
9873 // constructor.
9874 const auto LastStep = Seq.step_end() - 1;
9875 assert(LastStep->Kind ==
9876 InitializationSequence::SK_ConstructorInitialization);
9877 const FunctionDecl *Function = LastStep->Function.Function;
9878 auto Candidate =
9879 llvm::find_if(Seq.getFailedCandidateSet(),
9880 [Function](const OverloadCandidate &Candidate) -> bool {
9881 return Candidate.Viable &&
9882 Candidate.Function == Function &&
9883 Candidate.Conversions.size() > 0;
9884 });
9885 if (Candidate != Seq.getFailedCandidateSet().end() &&
9886 Function->getNumParams() > 0) {
9887 Candidate->Viable = false;
9888 Candidate->FailureKind = ovl_fail_bad_conversion;
9889 Candidate->Conversions[0].setBad(BadConversionSequence::no_conversion,
9890 InitE,
9891 Function->getParamDecl(0)->getType());
9892 }
9893 }
9894 CurrentParameterCopyTypes.push_back(Entity.getType());
9895 }
9896
9897 ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE);
9898
9899 if (ShouldTrackCopy)
9900 CurrentParameterCopyTypes.pop_back();
9901
9902 return Result;
9903}
9904
9905/// Determine whether RD is, or is derived from, a specialization of CTD.
9906static bool isOrIsDerivedFromSpecializationOf(CXXRecordDecl *RD,
9907 ClassTemplateDecl *CTD) {
9908 auto NotSpecialization = [&] (const CXXRecordDecl *Candidate) {
9909 auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(Candidate);
9910 return !CTSD || !declaresSameEntity(CTSD->getSpecializedTemplate(), CTD);
9911 };
9912 return !(NotSpecialization(RD) && RD->forallBases(NotSpecialization));
9913}
9914
9915QualType Sema::DeduceTemplateSpecializationFromInitializer(
9916 TypeSourceInfo *TSInfo, const InitializedEntity &Entity,
9917 const InitializationKind &Kind, MultiExprArg Inits) {
9918 auto *DeducedTST = dyn_cast<DeducedTemplateSpecializationType>(
9919 TSInfo->getType()->getContainedDeducedType());
9920 assert(DeducedTST && "not a deduced template specialization type");
9921
9922 auto TemplateName = DeducedTST->getTemplateName();
9923 if (TemplateName.isDependent())
9924 return SubstAutoType(TSInfo->getType(), Context.DependentTy);
9925
9926 // We can only perform deduction for class templates.
9927 auto *Template =
9928 dyn_cast_or_null<ClassTemplateDecl>(TemplateName.getAsTemplateDecl());
9929 if (!Template) {
9930 Diag(Kind.getLocation(),
9931 diag::err_deduced_non_class_template_specialization_type)
9932 << (int)getTemplateNameKindForDiagnostics(TemplateName) << TemplateName;
9933 if (auto *TD = TemplateName.getAsTemplateDecl())
9934 Diag(TD->getLocation(), diag::note_template_decl_here);
9935 return QualType();
9936 }
9937
9938 // Can't deduce from dependent arguments.
9939 if (Expr::hasAnyTypeDependentArguments(Inits)) {
9940 Diag(TSInfo->getTypeLoc().getBeginLoc(),
9941 diag::warn_cxx14_compat_class_template_argument_deduction)
9942 << TSInfo->getTypeLoc().getSourceRange() << 0;
9943 return SubstAutoType(TSInfo->getType(), Context.DependentTy);
9944 }
9945
9946 // FIXME: Perform "exact type" matching first, per CWG discussion?
9947 // Or implement this via an implied 'T(T) -> T' deduction guide?
9948
9949 // FIXME: Do we need/want a std::initializer_list<T> special case?
9950
9951 // Look up deduction guides, including those synthesized from constructors.
9952 //
9953 // C++1z [over.match.class.deduct]p1:
9954 // A set of functions and function templates is formed comprising:
9955 // - For each constructor of the class template designated by the
9956 // template-name, a function template [...]
9957 // - For each deduction-guide, a function or function template [...]
9958 DeclarationNameInfo NameInfo(
9959 Context.DeclarationNames.getCXXDeductionGuideName(Template),
9960 TSInfo->getTypeLoc().getEndLoc());
9961 LookupResult Guides(*this, NameInfo, LookupOrdinaryName);
9962 LookupQualifiedName(Guides, Template->getDeclContext());
9963
9964 // FIXME: Do not diagnose inaccessible deduction guides. The standard isn't
9965 // clear on this, but they're not found by name so access does not apply.
9966 Guides.suppressDiagnostics();
9967
9968 // Figure out if this is list-initialization.
9969 InitListExpr *ListInit =
9970 (Inits.size() == 1 && Kind.getKind() != InitializationKind::IK_Direct)
9971 ? dyn_cast<InitListExpr>(Inits[0])
9972 : nullptr;
9973
9974 // C++1z [over.match.class.deduct]p1:
9975 // Initialization and overload resolution are performed as described in
9976 // [dcl.init] and [over.match.ctor], [over.match.copy], or [over.match.list]
9977 // (as appropriate for the type of initialization performed) for an object
9978 // of a hypothetical class type, where the selected functions and function
9979 // templates are considered to be the constructors of that class type
9980 //
9981 // Since we know we're initializing a class type of a type unrelated to that
9982 // of the initializer, this reduces to something fairly reasonable.
9983 OverloadCandidateSet Candidates(Kind.getLocation(),
9984 OverloadCandidateSet::CSK_Normal);
9985 OverloadCandidateSet::iterator Best;
9986
9987 bool HasAnyDeductionGuide = false;
9988 bool AllowExplicit = !Kind.isCopyInit() || ListInit;
9989
9990 auto tryToResolveOverload =
9991 [&](bool OnlyListConstructors) -> OverloadingResult {
9992 Candidates.clear(OverloadCandidateSet::CSK_Normal);
9993 HasAnyDeductionGuide = false;
9994
9995 for (auto I = Guides.begin(), E = Guides.end(); I != E; ++I) {
9996 NamedDecl *D = (*I)->getUnderlyingDecl();
9997 if (D->isInvalidDecl())
9998 continue;
9999
10000 auto *TD = dyn_cast<FunctionTemplateDecl>(D);
10001 auto *GD = dyn_cast_or_null<CXXDeductionGuideDecl>(
10002 TD ? TD->getTemplatedDecl() : dyn_cast<FunctionDecl>(D));
10003 if (!GD)
10004 continue;
10005
10006 if (!GD->isImplicit())
10007 HasAnyDeductionGuide = true;
10008
10009 // C++ [over.match.ctor]p1: (non-list copy-initialization from non-class)
10010 // For copy-initialization, the candidate functions are all the
10011 // converting constructors (12.3.1) of that class.
10012 // C++ [over.match.copy]p1: (non-list copy-initialization from class)
10013 // The converting constructors of T are candidate functions.
10014 if (!AllowExplicit) {
10015 // Overload resolution checks whether the deduction guide is declared
10016 // explicit for us.
10017
10018 // When looking for a converting constructor, deduction guides that
10019 // could never be called with one argument are not interesting to
10020 // check or note.
10021 if (GD->getMinRequiredArguments() > 1 ||
10022 (GD->getNumParams() == 0 && !GD->isVariadic()))
10023 continue;
10024 }
10025
10026 // C++ [over.match.list]p1.1: (first phase list initialization)
10027 // Initially, the candidate functions are the initializer-list
10028 // constructors of the class T
10029 if (OnlyListConstructors && !isInitListConstructor(GD))
10030 continue;
10031
10032 // C++ [over.match.list]p1.2: (second phase list initialization)
10033 // the candidate functions are all the constructors of the class T
10034 // C++ [over.match.ctor]p1: (all other cases)
10035 // the candidate functions are all the constructors of the class of
10036 // the object being initialized
10037
10038 // C++ [over.best.ics]p4:
10039 // When [...] the constructor [...] is a candidate by
10040 // - [over.match.copy] (in all cases)
10041 // FIXME: The "second phase of [over.match.list] case can also
10042 // theoretically happen here, but it's not clear whether we can
10043 // ever have a parameter of the right type.
10044 bool SuppressUserConversions = Kind.isCopyInit();
10045
10046 if (TD)
10047 AddTemplateOverloadCandidate(TD, I.getPair(), /*ExplicitArgs*/ nullptr,
10048 Inits, Candidates, SuppressUserConversions,
10049 /*PartialOverloading*/ false,
10050 AllowExplicit);
10051 else
10052 AddOverloadCandidate(GD, I.getPair(), Inits, Candidates,
10053 SuppressUserConversions,
10054 /*PartialOverloading*/ false, AllowExplicit);
10055 }
10056 return Candidates.BestViableFunction(*this, Kind.getLocation(), Best);
10057 };
10058
10059 OverloadingResult Result = OR_No_Viable_Function;
10060
10061 // C++11 [over.match.list]p1, per DR1467: for list-initialization, first
10062 // try initializer-list constructors.
10063 if (ListInit) {
10064 bool TryListConstructors = true;
10065
10066 // Try list constructors unless the list is empty and the class has one or
10067 // more default constructors, in which case those constructors win.
10068 if (!ListInit->getNumInits()) {
10069 for (NamedDecl *D : Guides) {
10070 auto *FD = dyn_cast<FunctionDecl>(D->getUnderlyingDecl());
10071 if (FD && FD->getMinRequiredArguments() == 0) {
10072 TryListConstructors = false;
10073 break;
10074 }
10075 }
10076 } else if (ListInit->getNumInits() == 1) {
10077 // C++ [over.match.class.deduct]:
10078 // As an exception, the first phase in [over.match.list] (considering
10079 // initializer-list constructors) is omitted if the initializer list
10080 // consists of a single expression of type cv U, where U is a
10081 // specialization of C or a class derived from a specialization of C.
10082 Expr *E = ListInit->getInit(0);
10083 auto *RD = E->getType()->getAsCXXRecordDecl();
10084 if (!isa<InitListExpr>(E) && RD &&
10085 isCompleteType(Kind.getLocation(), E->getType()) &&
10086 isOrIsDerivedFromSpecializationOf(RD, Template))
10087 TryListConstructors = false;
10088 }
10089
10090 if (TryListConstructors)
10091 Result = tryToResolveOverload(/*OnlyListConstructor*/true);
10092 // Then unwrap the initializer list and try again considering all
10093 // constructors.
10094 Inits = MultiExprArg(ListInit->getInits(), ListInit->getNumInits());
10095 }
10096
10097 // If list-initialization fails, or if we're doing any other kind of
10098 // initialization, we (eventually) consider constructors.
10099 if (Result == OR_No_Viable_Function)
10100 Result = tryToResolveOverload(/*OnlyListConstructor*/false);
10101
10102 switch (Result) {
10103 case OR_Ambiguous:
10104 // FIXME: For list-initialization candidates, it'd usually be better to
10105 // list why they were not viable when given the initializer list itself as
10106 // an argument.
10107 Candidates.NoteCandidates(
10108 PartialDiagnosticAt(
10109 Kind.getLocation(),
10110 PDiag(diag::err_deduced_class_template_ctor_ambiguous)
10111 << TemplateName),
10112 *this, OCD_AmbiguousCandidates, Inits);
10113 return QualType();
10114
10115 case OR_No_Viable_Function: {
10116 CXXRecordDecl *Primary =
10117 cast<ClassTemplateDecl>(Template)->getTemplatedDecl();
10118 bool Complete =
10119 isCompleteType(Kind.getLocation(), Context.getTypeDeclType(Primary));
10120 Candidates.NoteCandidates(
10121 PartialDiagnosticAt(
10122 Kind.getLocation(),
10123 PDiag(Complete ? diag::err_deduced_class_template_ctor_no_viable
10124 : diag::err_deduced_class_template_incomplete)
10125 << TemplateName << !Guides.empty()),
10126 *this, OCD_AllCandidates, Inits);
10127 return QualType();
10128 }
10129
10130 case OR_Deleted: {
10131 Diag(Kind.getLocation(), diag::err_deduced_class_template_deleted)
10132 << TemplateName;
10133 NoteDeletedFunction(Best->Function);
10134 return QualType();
10135 }
10136
10137 case OR_Success:
10138 // C++ [over.match.list]p1:
10139 // In copy-list-initialization, if an explicit constructor is chosen, the
10140 // initialization is ill-formed.
10141 if (Kind.isCopyInit() && ListInit &&
10142 cast<CXXDeductionGuideDecl>(Best->Function)->isExplicit()) {
10143 bool IsDeductionGuide = !Best->Function->isImplicit();
10144 Diag(Kind.getLocation(), diag::err_deduced_class_template_explicit)
10145 << TemplateName << IsDeductionGuide;
10146 Diag(Best->Function->getLocation(),
10147 diag::note_explicit_ctor_deduction_guide_here)
10148 << IsDeductionGuide;
10149 return QualType();
10150 }
10151
10152 // Make sure we didn't select an unusable deduction guide, and mark it
10153 // as referenced.
10154 DiagnoseUseOfDecl(Best->Function, Kind.getLocation());
10155 MarkFunctionReferenced(Kind.getLocation(), Best->Function);
10156 break;
10157 }
10158
10159 // C++ [dcl.type.class.deduct]p1:
10160 // The placeholder is replaced by the return type of the function selected
10161 // by overload resolution for class template deduction.
10162 QualType DeducedType =
10163 SubstAutoType(TSInfo->getType(), Best->Function->getReturnType());
10164 Diag(TSInfo->getTypeLoc().getBeginLoc(),
10165 diag::warn_cxx14_compat_class_template_argument_deduction)
10166 << TSInfo->getTypeLoc().getSourceRange() << 1 << DeducedType;
10167
10168 // Warn if CTAD was used on a type that does not have any user-defined
10169 // deduction guides.
10170 if (!HasAnyDeductionGuide) {
10171 Diag(TSInfo->getTypeLoc().getBeginLoc(),
10172 diag::warn_ctad_maybe_unsupported)
10173 << TemplateName;
10174 Diag(Template->getLocation(), diag::note_suppress_ctad_maybe_unsupported);
10175 }
10176
10177 return DeducedType;
10178}
10179